If you aren't terribly budget sensitive, I can strongly recommend the Ambassade on the Herengracht, which is where I try to stay when I can. Nice people and comfortable rooms.

If you want something a little different, the Grand Hotel Krasnapolski (sp?) on the Dam has some apartments that they rent out. They don't seem to be available through the main website, but a google search on the hotel hame and apartment* brought it up for me.

I've gotten good rates at the Sofitel, and that is a good location and my room was fine.

As said before, the Hilton is a bit further out, but is close to a tram line so isn't really all that inconvenient. If you can find a good rate it might be worth it.

Amsterdam has an abundance of small hotels and some browsing around will turn up many options. After that tripadvisor is your friend.