I have a couple drum machines and if one doesn't have the sound I want, I can usually find it in the other one. I have a Zoom Rhythmtrak 123 which is probably about $150 new, and I have an Alesis SR-16 which is also probably about $150 new. They are great. I find I use the Zoom for more rock stuff, and the Alesis for more of the dance and hip hop based stuff I do, but they both have a wide variety of kits that work well.
I also have Logic and use a MIDI controller with that that is called the Trigger Finger...it's made by....oh shoot, I just posted it in the hip hop forum....I can't remember who makes it, but it looks like an MPC with the pads and everything so I like to use that a lot too, just to have more control over my software based drums.
I'd say you can't really go wrong with one of the two that I have. They've served me well for almost 8 years.