Well--my project list is:
PrimeGrid--GPUGrid--SETI--Einstein--Milkyway--Rosetta--Collatz--ABC--Docking--World Community Grid--NFS--Climateprediction--EDGeS--Lattice Project--Yoyo--Boincsimap--AlmereGrid & LHC@home.
So I mix it up quite a bit---My numbers went up quite a bit lately when I got a pair of GTS 450 cards (both seem to be working well for me)
I still like the straight science projects like SETI & I'm interested in things like Orbit, Einstein & other cosmological projects......I do the numbers projects to get numbers
I keep a number of medical projects going because it feels good to do so......