I remember being quite intrigued by the designs of Solrock and Lunatone when i first saw them in pokemon ruby, they were so mysterious and unique and really fit the psychic arena. I was a bit disapointed by their combat performance though. It's always such a shame when a pokemon with a super cool design isn't very strong.

As for my favorite Rock-type, it's gotta be Sudowoodo. No plant dual-type but close enough. ;)

Oh, I adore Sudowoodo too <3 With its goofy lil' dance!
But yeah, I totally wish the two space rocks had a little more viability in battle, but if you bulk 'em up a bit with Cosmic Power, they can sometimes really work! Plus, they just remind me of my favorite location in any pokemon game, Meteor Falls, so they're just very sentimental to me ;;

They'd be better if Rock was a better type, but even kids brute-forcing their way through the games figure out not to use it. [strike/] Inb4 Game Freak eliminates types instead of balancing them, like they did with HMs. [/s]