I'm doing the same research, here's my findings:
Mag 3 ($40): Best bang for the buck, hands down. Can be for for $40 online. Down side is that some same it's a fairly noisy pump compared to the compitition. If noise is not a real issue, here's your pump. Some have had problems with the barbs leaking, but if your careful, most are fine.
Ehiem 1250 ($70): Quality, solid performing pump, been around the block, and most love there's. It's is quiet, but a tad larger than some pumps, if that matters.
Hydor L35 ($50): New kid on the block, L20/25/30's are getting shaky reviews among watercoolers, don't buy the previous models. The L35 is the newest which is similar to the L30, but is more efficient, uses less energy, and is said to be fairly quiet. If this pump lasts and doesn't leak, it's the pump I'll be getting.
Swifty 600 ($70-80?): Similar to Ehiem, quiet, tested, quality. This pump has a very high overhead, and less flow, so the only reason I'd buy this pump is if I were using restrictive or multiple blocks. (Or if I could find it cheaper)
I'm personally looking at the Hydor L35. If it gets good reviews, it's the best bang for the buck for my needs. I'm looking for a cheap and quiet pump for a cpu and vga block.
