Originally Posted by DeltaFire
The Kurzweil keys were great, the K2000 and K2500 - fine machines. (and heavy).
Recently tried the semi weight keys on a MAudio Axiom, and they were delightfully nice.
I agree on the Kurzweil keyboards. I have a K2600SX and it is the closest to real hammer action of the many keyboards I own. You can also get these fairly cheap on eBay and they are built really well. I have had mine for almost 12 years now with no problems. It is a great midi controller besides being a monster synth. You probably only need the K2000 vintage since you really don't care as much about the synth capabilities.
I have an M-Audio Axiom 61 and, while it is decent, it is nowhere near the feel of the Kurzweil. Another possibility is the Casio Privia PX-130 keyboard. I have one of those and, while not a great midi controller per se, it does have a pretty decent feel to it and it is inexpensive. You can try them out in any Guitar Center to see if you like it.