I highly recommand Enlight 7237 because that's what I'm currently using, and I have it for more than 2 years now. Let's just say that my mobo may change once in a while, but this case will stay probably until ATX standard die out or that I move on to a full tower case. I got it when I still have a socket 7, P1 CPU, but now I have a slot 1, P3 CPU.
The other good mid-tower case would be the Inwin A500, but it only had 3 5.25" bays, which is not enough for me. The default Inwin A500 comes with a 235W PS that had a power switch on the back, which is good. For Enlight 7237, it comes with a 250W PS without the power switch, so the first thing I did was to get a 300W PS with the power switch and UIL standard.
BTW, I got a SCSI setup, so the more 5.25" bays the better. Although Enlight 7237 isn't great as a stock case, it is very upgradable, and once upgraded, it stand tall next to Inwin A500 (Hehe... must be the extra 5.25" bay)!! =)
Anyway, this is the place that I got all my cooling fans. He showed some pretty good pictures with those cases modify. I haven't gone that far yet... maybe in the near future....
PS. At some web sites, I saw Enlight 7237 selling for less than $80, which is cheaper than Inwin A500. I hope those info helps you out. =)