Surly's Bridge Club hits the sweet spot of capability, versatility and affordability. It'll get you around town, out for an overnight or across a continent over all manner of terrain without breaking the bank. It's not a slug on pavement but has plenty of tire clearance for unpaved adventures. This version rolls on 700c wheels with 41mm tires, ideal for mostly-paved riding but capable of handling a bit of dirt here and there.
"The Bridge Club quickly became the bike I reached for most often: perfect for exploring my local dirt roads, fun on trails, practical for commuting, and modest enough in appearance that I’ve never worried about locking the Bridge Club around town. Had this bike been available when I first started off-road touring – back when I was blissfully naive to the ‘benefits’ of spending thousands of dollars on a bike – I’d have jumped on it, no questions asked." -Cass Gilbert, bikepacking.com