The top 10 bestselling PS3 games really shows how FPS is the strongest genre on the platform. Six of the top 10 titles are an FPS. However...

[Serious_frusting]

If you take out COD FPS are not really that popular on PS3 when compared with the 360.

Without COD

PS3                                         360                   360 without Halo

1 car game                          1 msc                1 FPS

1 FPS game                         1 RPG               1 race

2 Sport games                    1 TPS                1 RPG

6 action games                  2 Action           2 msc

                                              5 FPS                2 action

                                                                        3 TPS 

Franchise can only be counted once eg, only 1 halo, 1 cod, 1 Uncharted.

PS3                                      360

1 Race                               1 msc

1 Sport                              1 RPG

1 Platformer                    1 TPS

2 FPS                                 1 Race

5 Action                           3 FPS

                                          3 Action

 

As you can see 360 owners prefer shooters in general, TPS/FPS. PS3 owners heavily favour action games. 

Cod is just stupidly popular. Outside cod and Halo, action games are the biggest genre.