Drums, everyone plays guitar. Even me. Horribly. Not enough people play drums. Fragment sentences.
Also, if you go guitar, a word of advice. You can get a digital amp that's about as good as a $1500 - $2000 tube for free by now. And, you know, you can get every digital amp that's that good for free, for various tones (generally no given amp is the best at any given tone, tube or digital). So, it might be better to get some fantastic speakers and, if necessary, a better soundcard, than to get an amp.
And to the seer of shadows - sure, if everything you play is in 4/4 you can go for interesting melodies on a guitar, while on drums you're a bit stuck. Now, try playing some DEP or Meshuggah polyrhythms on drums, or even Tool (for those few people who aren't incredibly skilled), and hey, interesting stuff on drums!