With Radeon HD 6950 1GB for gaming at 1600*900. Games like Metro 2033 and even processor intensive games like GTA 4 etc.
I would go with the i3 2100.See here for benchmarksyes phenom phenom II X4 975.
After considering your problem thoroughly I suggest that you go with the phenom X4.Afetr all even in gaming it isn't that much weaker than the i3.probably just 2-3 fps faster.A difference you won't even see as mostly 90%games are gpu bound and your 6950 will tear through them all.There isn't much sense in buying the i7 2600k after 2 years coz by then a much more powerful cpu will have been released.I myself own a i7 870 and I didn't upgrade to sandy bridge because there wasn't much difference in gaming.I am awaiting Ivy bridge to see whether it offers anything worthwile.Besides those 2 extra cores in the phenom will be useful in core dependandt games like crysis 2,gta 4,bfbc2@bluesc- yep, but due to my low budget for cpu, the phenom x4 955 comes in my budget. As you people say that an i3 2100 (which is priced at the same as 955) is faster than 955 in gaming, so am going with the i3.
After two years i will get an i7 2600k which have the same socket as the i3 i.e lga 1155 so i wont need to change my mobo. And then i will also get an more powerfull card than 6950.
But if i get some more bucks i will definately go with the i5 now.
What do you think about this plan?