Choosing between the Xbox 360 and PlayStation 3 comes down to which exclusive library appeals to you. Both consoles also share a massive multiplatform catalogue.
Roughly 90% of games (Call of Duty, GTA, FIFA, Assassin's Creed, Batman Arkham, BioShock, Skyrim, Red Dead Redemption) released on both, often performing better on Xbox 360 until late‑gen PS3 ports improved.
Ideal: Own both (cheap used) or play via backward compatibility on Series X|S (360) / PS Now/PC ports (PS3).