RPG wise....
Gamecube:
Paper Mario TTYD , Skies of Arcadia Legends, FF Crystal chronicles.
vs
PS3:
Legend of Heroes : Trails of Cold Steel series + Atelier Dusk series + Ar NoSurge : Ode to an unborn star + Fairy Fencer F + Final Fantasy XIII + XIII-2 + Resonance of Fate + Dragon Age II + Dragon Age Origins / Inqusition + Elder Scrolls Skyrim (+dawnguard) + Mass Effect series + Final Fanyasy X+X-2 HD remasater + Fallout 3 + Star Ocean the last hope + The Witcher II + Ni No Kuni : Wrath of the white witch + .... and on and on.
The amount of rpgs on the PS3 is like 20-30 times that of the Gamecubes, and most of them are higher quality.
As much as I love Paper Mario TTYD, it doesnt counter all the others the PS3 had.