Here's another vote for Rivendell. If your bike will fit them (many won't), I don't think you can go wrong with the Panaracer Pasela in 700x35. It's actually about 30.5mm wide, and at 240 lbs. I run mine at 75-80 psi. Nice cushy ride, and they roll well. I've also used them in 700x32 at 95-100 psi, but don't like them as well for most riding.
If there's no room under your brakes or between your fork blades for those, try Riv's Ruffy Tuffy, which I think is labeled 700x27 now. They designed it specifically to fit a wide range of modern bikes (which are generally pretty cramped for tire clearance). Rivendell recommends 95 psi for those, and that's what I use, but they say they'll go to 120 if you want to.