I like finding agencies that do good work...
http://fromupnorth.com/ but as you know you can find all that stuff already pinned on Pinterest :)
pinterest, behance, logopond, omgposters...
pinterest and behance are seeming to be the places to go these days, but i like httpster.net because it helps me avoid the black hole of clicking through tons of users
Depends on what kind of website you need inspiration for. For example, for hip sites I use Awwwards.
honestly i get a lot of inspiration from certain fashion label websites: comme-des-garcons, j-w-anderson, acnestudios to name a few.
Love love love this site
Don't have time to check individual websites so I usually look around Pinterest, behance, dribble, tumblr, etc. Also subscribed to loads of Facebook pages!
pinterest and behance
Another fan of http://ilovetypography.com! Their stuff is always inspiring. I also like ohsobeautifulpaper.com and even though their stuff is mostly invitations, I love seeing the different typography and they highlight different graphic designers so I am always visiting other blogs via this one!
Abduzeedo, BeautifulPixels, Smashing Magazine, Myfonts Tumblr page