Ok, I will begin by saying this phone is amazing. I love it to death! I came from an iphone and the upgrade was superb!
What is killing me right now is the damn screen on this thing. They gave me a Ferrari, then decided to key the exterior so it looked like Sh*T! (excuse my french).
What am I talking about? The infamous vertical lines/blobs that pop up at night when the brightness is low.
Sure, not an issue in the day, but what about when we use it at night, or are trying to watch a movie in bed??
Here is a picture I took with my other Galaxy S2 (small amount of lines).

SGS2 Screen issues - Vertical lines, blobs, spots
I have gone through 4 phones (2 black, back in november, 3rd one my brother got is not perfect, but much better than the pic. 2 white - over the span of 2 weeks) all with the same issue.
I had to trade in my white GS2s because they had the issue and thought ok, a 12/12/2011 build should NOT have this issue - I started it up and it looked decent.
Oh My God. I spoke too soon. I had glimpses of black when flashing and OMFG - this is just as bad as the pic I posted above if not worse!
FML - I'm going to return this POS (with this crap they call a screen).
The phone is amazing, I love it, the screen is just going to tank it for me.
Ugh. Sorry guys. /rant /vent /fuuuuuuuuu samsung SAMOLED!