Number 4
This is the perfect amount of fish for a 10 gallon And Tetras and Guppies do better in schools of 4 or more
Number 3 would do great also but I like the fish in Number 4
Number 1 would be extremely too crowded though. :
Number 2 could do alright but may be a teenytiny bit too crowded.
I agree the 1 gallon rule is stupid Especially when you are dealing with fish so tiny They dont need that much room and it costs hundreds of dollars for a bigger tank
If you do deside that you want a bigger tank which you probably wont need but just in case I just found a 20 gallon tank for only 36 bucks And I just cant believe it because most range from 200600 dollars Im getting that one and I cant wait I hope this helps you
http://www.petswarehouse.com/vpasp/shopexd.asp?id280989