I feel your pain. The PS3 is a good console but the limited *good* exclusives are few and far in between. The few that exist are amazing though, like Fat Princes, Ratchet & Clank and Uncharted but their isn't a real line up to it. Now if Sony could find other publishers and developers outside itself and actually built games that the machine was designed for, using 100% of the Cell processor and the Blu-ray capability, we will get somewhere.
Whereas with the 360, well, already they are chock full of plans with Fable 3, Gears of War 3, Halo: Reach, Halo 3: ODST, Mass Effect 2, Left 4 Dead 2 and the frankly amazing Alan Wake. However, it can be argued that if you have a mid/high end PC you can at least run half of these titles (some are 360 only though). Whereas PS3 exclusives are really PS3 exclusives and they tend to take their own sweet time in getting to players. Perhaps that the reason why the 360 Red Rings so often, its working all the damn time!.
I guess it comes down to what you want from the PS3. It is a great entertainment system as well as a great console but if your flavor of games is the Microsoft variety then save the money and stick to the 360, alternatively, upgrade your computer and wait for Diablo 3.