I ride Schwalbe Marathon Supremes on my 520. I like em'. Good puncture resistance, roll fast enough. I feel like they're unnecessarily expensive though. I bought some awesome puncture resistant Michelins' (sp.) for my Surly and they were half the price per tire that the Schwalbes were! Same quality. It's kind of a gamble, really.
If you can easily afford the Schwalbes, do it.
If you can't, keep searching and you'll find some that will do the trick.
"Things look different from the seat of a bike carrying a sleeping bag with a cold beer tucked inside." ~Jim Malusa
2009 Trek 520-Brooks B-17 Special in Antique Brown
2010 Surly Long Haul Trucker-Brooks B-17 Standard in Black
1983 Fuji Espree Single Speed-Brooks B17 British Racing Green