what makes a good CD player

I am impressed with the Ayre Minimum Phase (MP) filter. Other players and DACs using similar technology are PS Audio Perfect Wave, Meridian .2 players and Esoteric SA-50.

Here is a quick stab at it. A good drive mechanism and power supply - difficult to evaluate without listening - you will have to take the reviewer's word for it. All things being equal, balanced outputs are better, particularly if your preamp and preferably amplifier also have balanced inputs all the way through. There are solid state and tube CD players that sound wonderful, and the higher you go, the more the engineers imbue subtle sound qualities in their devices. Really becomes difficult to differentiate classical tube or transister sound signatures, they all just sound good. Digital format - having a nice upsampling DAC that can handle high resolution internal and external digital signals is more future proof than a player that only does internally read redbook CDs.

With that said, I don't think you are asking the right question. I think the CD player that sounds the most like music to you when its playing is the "best". Check out the following link and see one way to evaluate how good a particular system or piece of gear sounds to you. A particularly important tip RE sources - where the music starts. Reading reviews that resonate may be the "best" way to determine what you are going to like and then give it a whirl in your listening room. Buying used can the protect you from depreciation blues if you find you don't like it.

http://www.hawthornestereo.com/advice/judging.html

As 'knownothing' indicated, the ears rule, no matter what the tech or mechanical means are. As I have posted before, be bold. Try the Sony 595 for $60 at SonyStyle to see if it will satisfy you 'ears'. Many have said it does.

I see what you all are getting at, and I know its what sounds good to my ears. The problem is my ears arnt near any hifi stores and the nearest one is 2 hours away. So I need to be able to research without hearing, because if I don't like what I hear when I ultimately buy a piece of equipment Im going to have to send it back. I'll do that once or twice, but I can't just do it endless amounts of times. So I was hoping for a way to narrow down my search before my ears get to listening.

Perhaps a better approach is to ask folks on here about particular sound signatures you value. E.g. Must carry tune, depth of soundstage is critical to me, lushious midrange, etc. People can provide you with examples within a particular price range they feel would meet your interest/tastes