Which tank would be better?

[Calmwaters]

As some of you know I bought a sick girl when I bought my 5 healthy ones and she is currently liveing in a 5 gall bucket. Well today I plan on getting her a real home but wanted everyones opinions. These are the ones I am looking at:
This on is almost 2 gallons I like it because it comes in purple. LOL
Marina Goldfish Starter Kit - Aquariums - Fish - PetSmart
This on is 2 gallons I like this one because its pretty. LOL
Hawkeye Aquariums AquaView 360 Aquarium Kit - Aquariums - Fish - PetSmart
and the other one is just a rectangle shaped one that is 2.5 gallons and comes with a clear glass hood. Its about $13.00. I have extra gravel and plants I can use to decorate with. A friend of mine has this one and it looks really nice when it is decorated. What I am looking for are the pros/cons of each one.

[1077]

Never heard of a person ,or a fish, complaining that they have too large a tank. Well,,, Almost never.

[Calmwaters]

LOL So I guess you are saying get the biggest one. LOL

[Jupiter]

The first one was the model I was PLANNING to buy for a future betta, until my uncle made it pretty clear he didn't want more tanks in my room...oh well. :/

The one you have is almost 2 gallons, but they have bigger sizes too. The one i was planning to buy is 2.65 gallons, and i believe they have a 3.3 gallon variant as well.

The round one...not really my style. I imagine it would be weird seeing your betta through that, and I'm not very comfortable with undergravel filters.

[AlexXx]

Id say go with the first one, it just looks nicer.

[ElmoFish]

I have a couple models of the first one, the 2 gallon and 3.7 gallon ones.. I have no real complaints except that the lids come completely off when you open them even tho they have hinges, which is sort of awkward, and the weird angles can make cleaning a little awkward.. I have a purple one that I actually wish I'd gotten a lighter color as I find it very dark..

[Calmwaters]

I decided on the last one here is a picture. They were out of the purple ones and only had the orange which I didn't really think would look good with her color. Here is a picture of her in her new home:

and one of just the home:

[dramaqueen]

Nice tank!!

[Calmwaters]

Thank you. I have a question should I leave the lid slightly open to be sure air can get in? It has to be open a little due to the cord for the heater but I was wondering if I should maybe leave it open maybe half an inch? She seems to like it. When she was in the bucket it was kind of dark and she didn't swim around alot now she is swimming and checking things out.
I thought of one more question.LOL Since I do not have a filter should I do water changes? On the Melafix it says to only do a change after 7 days of treatment so I am a little confused. I will get her a small filter when she is better to help with water quality but right now with the Melafix it says to remove the carbon and the small filters have carbon built into them.