I second 1and1.com. Great prices and excellent services and interface.
Professional. Largest in the US or world - works for beginner and massive corporate sites. You can look at its interface compared to something like GoDaddy and immediately tell you're in the hands of pros, not a marketing company. I host 40+ domains with them. And I've tried a half dozen other hosts but switched everything to 1and1 about five years ago.