What if I throw in the i3 2120 for purely gaming reasons, what then? Sorry just still debating on the 2120 seeing as it is a very good processor.
Depends on what sort of gaming you want/plan to do.
i3 is a good pick for games that can only leverage 1-2 cores (the bulk of what is out there right now) but i5 is a safer bet if you intend to either run some of the more demanding games like BF3 that can use 3-5 cores or have stuff running in the background while gaming.
I would personally pick i5 since I always have tons of stuff running in background even while gaming.