What settings for battlefield 3

My PC AMD Phenom II 955 BE
8GB GKILL RIPJAW
Sapphire 6870 1GB
Samsung spinpoint F3 500GB

Should I be playing Battlefield 3 on top settings at 1980 X 1080.

You won't play on ultra with 60 fps, but you should really be able to pull mostly high settings. Avoid deferred anti-aliasing but you'll probably get away with post processing on high. Don't turn shadows any higher than high, and if you need to drop some settings drop that setting first.

not that i've seen, i've seen all ultra on a 470 cause very eratic fps, massive swings between 10 and 40

Can't explain the bsod's but the game locking up can sometimes be related to unstable clocks or low voltage on the gpu or both. Particularly in BF3 as the game is picky about overclocks.

To be clear I run the game on full ultra settings with no deferred anti-aliasing, at never less than 60 fps, but that is with a heavily overclocked GTX 570 at the same resolution that you play at. You should stay on high settings (which look almost indistinguishable from ultra in the first place) and tick shadows down an extra notch if necessary.