This is what I do, Win7 for games, debian for work.

I like the dualboot nature as when in debian I have no excuse to startup a game and get distracted, when in windows I know I'm off work and I can relax.

Also having access to good command line tools is priceless - I'm not conversant with powershell, so maybe windows is good for this now, but being able to quickly grep/sed/awk/vi/etc is so useful.