I'm looking for my ideal tire, and would appreciate any input you guys have. My set of Continental Contacts that came with my Surly LHT are starting to crack around the rim, and I think it's time for something new. I've liked the Conti's, but want something a little more versatile.

I am looking for the following:

- Fat. I would like the new set of tires to be at least 700x37c. I think my bike can handle up to a 42 or 45 with my fenders. I want something that is going to be cushy but quick.
-Tough. I want to be able to take these tires on some gravel roads and even some mild single track. I'm going to want to take this bike on an adventure in the woods, but be able to handle the roads just as easily.
- Quick. I am interested in having one set of tires, where I can comfortably ride a century. I am going to keep the Conti's because they're not so far gone, but would like to use this new set as my primary tires.

Ideally, I would not like to spend 50-60 dollars a tire, and am thinking more around 25-40 per.

Is there anything like this? I've seen the Schwalbe Marathon Cross for a reasonable price, but do you think those tires would really wear and slow me down on the road?
I appreciate any input.

Charlie