Mainly I use my Macbook Air, and my specs are in my sig.
But I'll post my bro's desktop (because he lets me use it for gaming):
i7 980X 6-Core CPU, overclocked to 4.2GHz
ASUS Rampage III Extreme mobo
Corsair H70 Liquid Cooling
8GB DDR3 Corsair Gaming RAM, overclocked
2x SLI Nvidia GTX 460 GDDR5 768MB (this is bottlenecking his PC, he might upgrade it on Boxing Day or something)
2x 60GB Corsair Force series SATAII SSDs in RAID
1x 500GB Western Digital SATAII HDD
2x 2TB Western Digital MyBook Essential external USB3.0 desktop HDDs
D-Link Xtreme N wireless networking adapter
Silverstone Raven RV01 Gaming Case
3x Samsung SyncMaster E2220 1080p LCD monitors
Razer Anansi mechanical MMO keyboard (he doesn't like mechanical keyboards, but he spilled liquids on his Lycosa)
Alienware TactX gaming mouse
Xbox 360 Wireless controller receiver for PC (because for some reason he doesn't like gaming on KB/M unless it's WoW, and also because I bought a 360 steering wheel a couple years ago)
Beats 'solo' on-ear headphones for music, Tritton AX720s for gaming
some cheap 5.1 Altec-Lansing speakers (they were on clearance) for playing it loud