Hey all!

Sorry, I'm an advanced beginner if anything to digital photography, and I'm planning on making my first very major purchase. I've decided to pick a Canon camera. I don't know which one. Is any of these a great investment?: Powershot S50, G2, G3, G5. Let me give you the low prices, in case they may help:

S50--$333
G2--$309
G3--$439
G4--$442

How would it matter if I got the G2 rather than the G3 or G5? Or, rather than the S50?

Feel free to suggest other cameras and other brands. I am searching for good quality night and day, inside and outside, and good amount of options. Thank for listening. Great thanks to anyone who can help!

Thuan