Thinking of replacing my CPU

I am currently using an Athlon II 240 Regor and I think I cheaped out on my CPU. I would like to replace it with one of these, but can't decide which is the best value for my needs. I would like to get better frame rates in games. I am a gamer, but I am not an enthusiast and do not plan on overclocking.
Again I am looking for the best value in price vs performance, not the most powerful chip.

AMD Athlon II X4 635 Propus 2.9GHz $99.99
AMD Phenom II X4 925 Deneb 2.8GHz $129.00
AMD Phenom II X4 945 Deneb 3.0GHz $139.99

Why not just OC that 240 and see what happens. Then if you don't like the results you can buy a new CPU. I'm not sure that any of those CPUs will get you better frame rates. From what I've read most games don't use more than two cores anyway. And the speed of those processors isn't much more than what you already have. The only real difference is the L3 cache and I don't know how much of an effect that really has in gaming.

The Phenom II 945 does do significantly better in gaming, but that may have to do with the clock speed.
See here
I haven't tried overclocking yet. I am using the stock cooler. Is that a problem?

If you watch your temperatures carefully you can OC on stock cooling, but you may not get as high. Keep things below 60C at load (55C is even better). Turn the Ht Link speed down one notch (keep it around 2000 at all times). Set your ram to 667 first. Then move the clock up to 210 and see what happens. Run Prime95 and watch temperatures. If that works move up to 215 and retest. It's a process.

So maybe the 945 would be a good choice. Can't hurt to try the OC.