It's not GS' general reviewing of games that bothers me, it's the major GS reviews that get me. They "flopped" MP3, LoZ: TP, and now R&C by System Wars Standards, yet all of the major 360 games seem to get by unscathed. Gears of War? Halo 3? Bioshock? All 9.0+.
Prior to Halo 3's release, there had been many rumblings of bias towards MS, but most people didn't take it too seriously. The vast majority of people, including myself, thought that Halo 3 would be the next big flop, since GS' reviews had become so critical as of late, and the fact that Halo 3, after all, was just another Halo. Many figured that Halo 3 would suffer the same fate as MP3 and TP (and later R&C), a lowering of the score for being too similar to it's predecessors. When Halo 3 came out as a 9.5, fanboys from all sides gave a resounding, "WTF?" The R&C review only confirmed the fact that Halo 3 was overrated by the "new" Gamespot standards.
It's the inconsistency of GS' reviews that gets me. The spread of 2 whole points between games that are both very good (R&C and Halo 3) casts into doubt all of their review scores. Is a 6.5 that much worse than a 7.5? It makes the entire review system rather pointless.