I went for slicehost about a year ago right when they were bought by rackspace. At the time HN recommended them as the best choice by far, and I think they were. I never did have any problems with them at all this year, and everything from customer support to management interface has been great.

I'm a bit sad though that I'm also thinking about switching. Price/performance wise they're not even close to the top, plus they still don't have any data centers in Europe.