Fish are boring.
But if you want one so bad...I would consider a BETTA FISH.
Here is a bit about them::
How to Take Care of a Betta Fish
Betta splendensBetta splendens, also known as "bettas" and "Siamese fighting fish", are popular pets recognized for their friendliness, interactiveness, and relatively low cost for maintenance and care. Betta fish can prove to be man's best friend for up to four years. By following these simple steps you can help to ensure that your new friend has a happy and healthy stay with you.
Steps
Purchase your betta. There are some considerations for choosing your betta.
Visit your local pet store. You should have a general understanding of what to look for before purchasing your betta.
Observe the available bettas. There are a few qualities that you should look for when choosing a betta fish:
Color. Is the betta bright and vivid in color, or does it appear very dull and pale? Bettas come in a variety of colors, so don't be surprised by the choices available. Blues and reds (dark colors in general) are the most common.
Receptiveness. Does the betta respond to your movement at all? Does it appear to swim around rapidly at the sight of you, or does it merely sit at the bottom and sulk? You shouldn't repeatedly tap on the container, as you will only agitate the fish, but you should find a way to see if it pays attention to you. On the other hand, don't be afraid to buy a somewhat docile betta. Bettas will generally have many encounters with other people during the day, and may simply be taking a brief rest.
Overall health. Are its fins in good condition, or are they torn or otherwise damaged? Are the betta's eyes in good shape? Do you see any odd lumps (parasites) on its body? If you see anything highly out of the ordinary, you may want to consider another betta.
Prepare your betta's home.
Here are some points to consider:
Choose a home. In the wild, bettas inhabit Thai rice bogs. Hence, they are fitted to living in relatively shallow but spacious environments. However, you should still consider giving your betta a decent sized tank to help prolong its life, since waste can build up very quickly. Naturally, more water is better, but a 1 gallon tank is an excellent size for your betta fish.
If you choose a larger tank (5 gallons or larger), you may consider purchasing another type of fish to cohabitate with your betta (be sure to read the Warnings below).
Decorate your betta's home.
One of the betta's distinct features is its ability to breathe oxygen in both the air and the water, so you will not need to supply a filter or live plants but it will prefer it if you do. You might decorate your betta's home with gravel/colored stones, man-made plants, and a small cave-like structure to hide in (if your tank is large enough). A creative home is a happy home!
Do not use jagged rocks for the bottom of your tank, as they can and will shred your betta's fins. Smooth, colored stones are a good choice, as well as gravel/pebbles.
Be wary when buying hard plastic plants, as they can be rough on
your betta's fins. A good trick is to use the 'pantyhose test': If a plastic plant will snag a pair of pantyhose when rubbed against it, then it will damage your betta's fins.
While live plants aren't necessary, they are a great addition to a betta tank. Their appearance is better than the plastic or silk ones, and bettas love to lounge on leaves and to have a hiding place in which to sleep.
Prepare the water. If you use water fresh from the tap, use a water conditioner before you put it in the tank, as the chlorine and chloramines can harm your betta. Older sources may suggest aging the water, letting it stand for a period of time. It is best to use a water conditioner, since aging water will remove chlorine but not chloramine.
Bottled water is also effective. You still may want to treat it with water conditioner, though. Just don't use distilled water as it lacks vital minerals bettas need.
Consider adding aquarium salt (not to be confused with the table salt that you eat) to your tank. This acts as a "tonic" for betta fish, helping to relieve stress, as well as preventing the appearance of parasites such as ich.
Fill your tank. If your tank does not have a top cover, then fill it about 80% high. Bettas are very active fish and can jump over three inches when motivated, so this will ensure that it does not jump out of the tank.
If your tank does not have a top cover, you can a mesh cloth over the top to ensure that it does not jump out. It will be much happier if it has access to lots of air as it does breathe from the water as well as the air we breathe.
Test the water temperature. Be sure that your tank is placed in an environment that maintains the temperature of about 78ºF (+/- 3 degrees). Purchasing a small heater is a good idea, since the temperature of the water is likely to be much cooler than room temperat
Be gentle.
Add your betta. Float the bag with the betta inside it as you purchased it in the tank water for 20 minutes. This allows for the temperature to adjust. Then pour some of the aquarium's water into the bag every 10 minutes. Finally, with a net, put the betta fish in his new home. Don't pour the pet store's water into the tank as it could contaminate your water. Using a net can damage the fins of a betta - you can just dump the betta in the tank, but be careful.
Feed your betta.
Your betta's diet should consist primarily of pellets. Bettas are meat eaters and will happily munch on bloodworms and brine shrimp (sea monkeys), but these serve better as occasional treats. Feed them 2 to 3 times per day—generally once in the morning and once before bed.
Be sure to clean up any extra food that your betta does not eat. Similarly, be sure to watch your betta fish to see if he spits up any food.
A diet high in protein yet varied is important. Flakes, live food, freeze dried, pellets, whatever works best for you, but keep it varied. If you don't keep your fishes diet varied, it may become constipated. Constipation in a betta resembles swim bladder disease in which they are unable to maintain their balance. All is not lost. Feed him a bit of krill soaked with Castor oil, then no food for a day or two he will be fine.
Though live food may be more exciting to watch, freeze dried products still work great. They are also safer and free from potential parasites.
Don't overfeed your betta, no matter how hungry or cute he/she seems! Your betta's stomach is about the size of its eyeball, so keep that in mind.
Be sure to clean your betta's tank as needed.
Remove your betta from the tank. You can use a fish net.
Place it into a small dish. You should fill it with the old, dirty water from the tank. It is important that you keep it in its old water, as you do not want to shift its living environment radically.
Clean the tank. Clear up any buildups on the side(s).
Clean your accessories. Be sure to remove any buildup on your plants, stones, and anything else in the tank.
Replace some of the water. Don't change all of the water at once, as the abrupt shift in the environment can harm your betta. You should only change about 50% of the water in the tank at a time. For the other portion, use clean water of about 78ºF. Be wary of shifting the water temperature too drastically when you reintroduce your betta to the tank, as it may affect your betta. Don't forget to add any water conditioner, aquarium salt, and anything else, as needed.
Keeping a spare jug of water is helpful.
You should do this partial water replacement about once a week for a one-gallon tank.
For a partial water change of 20% per week, it is not necessary to remove the fish. Simply reach in with a gravel vacuum (a siphon with a wide opening at one end) and "vacuum" the debris out of the gravel or other substrate.
Tips'
Bettas' are members of the Anabantoid family (gouramies are in this family) and have a back-up breathing system that allows them to breathe surface air. However, they still require a filtration system in their tanks and aeration. Bear in mind the long-finned varieties do best with as little current as possible.
Bettas recognize their owners and will actually learn faces and games. Keep your betta company and say "hi" once in a while, so he learns who you are! Bettas can and do recognize people (mainly because they associate you with feeding time).
Female bettas are typically smaller and without the beautiful plumage that males possess. However, they can still be equally as beautiful in their own way—and feisty!
If your betta gets sick, treat it with a proper antibiotic. You can purchase these at your local pet store.
You can use a clean turkey baster to suck up any pellets that fall to the bottom of the tank. This helps to keep your tank relatively clean.
If you don't want to spend a ton of money on a bowl or rocks, check your local Dollar Store. They might have some pretty amazing fish equipment, and for the low price of $1!
WARNINGS!!
Male bettas cannot live with other male bettas. They are named Siamese Fighting Fish for a reason! In an aquarium setting, they will fight to the death in order to protect their living space, regardless of the size of the tank. If your tank does not have a partition, do not risk losing one or both of your bettas by allowing them to live together.
Also, when a male betta fish sees its reflection in a mirror, it will think it is another fish and will try to attack it. While this may be cool to look at, and is also an interesting activity for science classes, doing this too much will stress the fish out and can make them very sick.