I consider myself a beginner, been happy with my 10 gallon.
I've had fish off and on when I was little, but I don't remember maintaining the tank, and assuredly not cycling the tank properly or cleaning properly for that matter. It has been several years since I sought to own fish, but after living in a pestles apartment for some time I ventured out to get a 10 gallon tank, not because of price, but because of space constraints. (I have a 20 gallon in my parents basement that I could have used) First I don't mind doing water changes 2-3 times a week, the tank takes no more than 30 minutes of maintenance a week. Second I didn't "overstock" my tank and I understand what the limits of the tank are with out stressing out the fish. I think it boils down to commitment, what types of fish you want and how much time do you want to spend maintaining a tank. I luckily got some good advice about my tank, what types of fish I could and how to set it up. Its been going for a month now with out any issues or "disasters", well a month with fish, a month of cycling it fleshless. I currently have 6 Zebra Danios in there, they have been quite happy, they always come to great me, and they swim around and play at full bore all day long, and they enjoy a recent addition of a larger plant that also floats on the top and think its great fun to hide in it, and swim through it. The sometime school, but they are usually found scattered though out the tank chasing each other or swimming around at mock 10 or trying to show off and chasing eachother. They all seem quite happy. *BOUNCINGS My tank has been quite stable and I find it easy and predictable to keep an eye on, I test the water every few days to ensure that everything is going well and could probably get away with one or two water changes a week if I needed. I do tend to agree that 20 gallons or larger is better for a beginner, I say so only because it allows more of a tolerance for mess ups. Any good beginner with a good guide and someone in the shop who can answer questions and make good recommendations is far better off then someone who "wings it" with a larger tank IMHO. On top of that for student housing and small apartment living a 10 gallon tank is the perfect size for me, and I do enjoy keeping fish. I have had fish on and off for most of my life, although I did little to "help out" because I was a kid or just general lack of understanding, I have had several tanks, from a 20 gallon, a 2 gallon, and a 5 gallon. The 10 is a breeze in comparison to the smaller tanks. I personally love my 10 gallon, and I cant wait to find enough space for a larger 50 gallon tank. Just some food for thought, I did help my roommate with a little 2 gallon and a Zebra Danio as well and despite sever sharp comments or criticism he lived happily in there for the entire year with out issues until we put him in my tank with some friends. None of the fish have shown stress, or illness and I have had a very successful healthy 10 gallon tank with even a move thrown in so far. With a little research, a good person to ask questions and some time you can start off with a successful 10 gallon tank that is stable and has happy healthy fish.