I freaking love my Geodude (well, he's a Graveler now, and will inevitably become a Golem). Rock Pokémon rock. I know, I know, they suck against a bunch of things, but the things they don't suck against they basically bulldoze through fairly unscathed. I always keep 1-2 rock types whenever I am roaming the wild.

But you're absolutely right that it's stupid how weak rock Pokémon are to certain things. I mean, water? Really? Why?

I have mixed feelings regarding ghost type Pokémon, too. My Haunter is great in a lot of situations but the fact that every non-normal/fighting attack hits a ghost type strikes me as odd. Especially things like Ground and Rock... not that I want Rock to suffer any further than it already does. xD