I fish/have fished with everything from the cheapest, crappiest Crystal River (South Bend) lines to Scientific Angler's Mastery GPX lines. In the cheap line catagory, the best line by far is the Scientific Angler's Air Cel lines and the Cortland 333+. The Air Cel is typically a $20 line, with the 333+ being a $30 line. The Air Cel has a couple variants - a short half-length line (54 feet) Weight Forward tapered line, and a full length (85 feet) line that comes in WF, DT, or level flavors. If you don't need distance, the short lines are great. Right now I'm using the crap out of 2 of the short lines - a 5 weight and a 6 weight. They're great knock around lines - they cast reasonably well, and they work great for my small stream and panfish rods.
I would avoid Crystal River lines, and the Cortland Fairplay lines. Both are pretty much junk, and for the same cash you get a better line with the Scientific Anglers lines.
Cabela's has some good sales pretty regularly, in fact I think there's one going on now, where you can get one of their basic Prestige lines for $21 plus shipping. These are OK lines - not as good, IMO, as the Air Cel, but better than the Fairplay lines.
When you can swing the extra cash - a Cortland 444 would be a better performer, or even better, one of the Sci Angler's Mastery lines. I've heard good things about the AirFlo lines, but I haven't used them yet.