Got a couple of choices (But all means getting the SGS)
1) Wait for SGS3
2) Get a one year contract with SGS2, then get an upgrade for SGS3
3) Get a SGS2 sim free and use it until it breaks before getting SGS4 (maybe)?
Hehe... What I mean is that the SGS is the top phone right now, and I strongly suspect that with it coming up with practically yearly upgrades, this line of phones could easily stay at the top for a couple more years.
IMHO, if you want a smartphone get SGS2. When you get it, look out for some of the common problems highlighted and test it. Then see if you want to return it. But really suggest you don't be too mean about it.
I mean people complain about not enough phone memory, but they knew about the memory before they buy the phone and its a lot more than other phones, and enough in my opinion. They also complain about the screen in red blotches in black wallpaper in a BLACK room. But if its not serious enough to effect everyday use, is it that big a problem. (I do have a red tinge but its not in blotches and I still love the screen.)
So yeah.... get it. Test it out. Find the right one. And be happy. And if you get the SGS3, I am going to be soo envious.