Should i get a PS3 or X360? (Wii owner)

[ziff]

1.RE5, GTA4, Assassin's Creed, Halo 3, MOH, Bioshock all are on X360.
2.GTA 4 has two chapter expansions exclusively on X360.
3.Most multiplatform game on X360 has better graphics than PS3.
4.Ps3 expensive.