I'm quite fond of my Columbia 26. She's built pretty well. As with any boat of that vintage, you'll have work to do. Interior layout isn't bad. The head comes standard with overboard discharge, so you may need to look for one with a holding tank added already. The cockpit is a bit small for more than 2, but it's workable. I've overnighted with 4, and it's cramped, but doable. I'm 6 feet and the V-berth is quite comfortable.
I don't like the engine well on the Bristol. I also don't care for centerboarders. I'd stay away from the Bristol, just for those reasons.
The Pearson and Columbias look quite comparable, though I've never been in the Pearson. The Columbia has a slightly deeper draft, if that's an issue.
The S2 that 7T7 mentioned isn't bad, but watch for delamination or water in the cored hull.
I'd also recommend you look at the Cape Dorys and Contessas, though they're in a slightly different price category. ;-)
I had a Pearson 26 for about 10 years and my wife and I cruised each summer for 2-3 weeks at a time from Western Long Island Sound to Newport, Block Island and Martha's Vineyard. A solid boat that sails well. My major complaints were a lot of weather helm if overpowered and the outboard would come out of the water in short steep waves making powering an ordeal. I prefer the Pearson to the Columbia and Bristol. I don't like the construction quality of S2s.
I have a 1973 P26. It was my first "big" boat and suited me well to learn on. It is a pretty fast boat (with a 150% geny) and easy to maintain (very little woodwork). I would recomend it for lake sailing and calm coastal cruising. If you are looking for a more rugged boat that is better in rough weather but maybe a little slower, check out the Bristol 24. Unlike the 26 it is a full keel boat and is very similar to a cape dory in sailing performance. There is one moored right next to my P26 and it is a nice boat. More shear to it and it looks like it would be a drier boat. It also has an enclosed outboard well which makes it look better and helps it from getting swamped. I think it also has a 1/4 berth. The P26 is a great boat but it pounds heavily in steep rough seas. I have scared myself enough on Lake Champlain to know that it might not be the best boat for the ocean.