We have an S2 and it is nice. It is fast, it has an awesome screen. Samsung has done lots of updates for it.
My only quibble is that the touch seems a little off and if I type on it, I always type horribly. I don't think there is a way to calibrate that, so check it out when you get it if that is the sort of thing that bugs you.
If the lesser screen and the 16x9 format isn't a deal breaker, the Galaxy E is cheaper and fairly nice if you don't need the extra horse power. I gave one of those to my aunt and she loves it.