I would like to bring to your attention a review i wrote regarding the ATI RADEON 4850.
The difference of this review from the rest, is that the benchmarks are done on a completely overclocked system (nothing crazy) and the 4850 is overclocked too@680mhz.
These tests were done only at 1680x1050 and there are five categories. 8800GTX without AA, 3870 w/o and with 4xAA, as well as 4850 w/o and with 4xAA. We are talking 50+ benchmarks for each category.
You can find the translated version of my review here and the original Greek version here, in case you can read greek. Be warned though, the english google translation is very very off.
To save you the trouble you can find the .xls file of the test here (rapidshare)
If you don't have excel installed you can download the jpgs of the test here (also rapidshare).