No one can beat the sedo.com parking program due to its high payout. parked.com is also very good. These provide good templates.
What I do when I first register a domain is to fist place them on Sedo, this does several important things: It gets the domain listed for sale It gets the domain indexed by Google (in a few weeks usually) It gets the domain earning something. (even if only a tiny amount) I have nearly all of my 900+ domains listed on Sedo for sale even though I only have a few parked there and this paid off recently when I sold a .info I purchased for $.99c for $1000 Sedo won't make you much in parking (unless it is a top parking name) but I think it is a good place to first place your domains considering the above. Once the domains are indexed by Google which is very important then leave them there for another week or so and if any of those domains bring in some revenue then you might as well leave them there. For the domains that bring in clicks but low revenue then optimize them with the tools they provide. Now for all the domains that don't perform at Sedo and once they have been indexed by Google you should now move them to another couple of parking companies (the ones mentioned already on this thread like Parked, Fabulous etc). But make sure you leave all your domains listed for sale at Sedo (if you want to sell them that is) even if you park them somewhere else. Development should be your ultimate goal!
I really think all parking domains try their best. The reason is they want you to do good so they do good. Plus the competition will make them perform or die. So I can't imagine any of them being *bad* Now as for pool and snapnames and those that buy up expired domains in direct opposition to the heart of the rules, they can go stuff themselves as everyone knows this is my opinion of them. But I like all parked companies. We just have to make advertisers aware we convert good for them!