I don't know enough about slow cookers to give you advice on a particular brand, to be honest, but the one thing I can say for certain is find one with the lid that latches down. They are spill proof, so taking your crockpot of food to your friends party in the car is no longer hard. No spills when going around the corner. I have this one:
Amazon.com: Hamilton Beach 33262 Stay or Go 6-Quart Slow Cooker: Kitchen Dining
It's a cheapie, but it is pretty consistent with heat. And as far as spending for the programmable ones - get one like this, use a plug in timer like you'd use on a lamp. Saved money, and I think you'll find you don't use that feature all that often.