Budget single disc player-under $600

NAD 515 ? NAD 545? Marantz 5003 ? Cambridge 340 and 540?, Music Hall 25.2? Best sound? Best transport? Best at format versatility?
I want to keep to these choices since these are the ones I can
see at local two channel retailers. Thanks
The Marantz is pretty well built and sound very decent. I sent one to a friend and he loves it. Now it's mated with a Scott Nixon Chibi DAC and really sings, so it works well as a transport too.
There is a JD-100 on Audiogon for $560. Tube rolling yields excellent results with this player.
The advantage of buying used equipment on Audiogon is you get more for your money and if you don't like it you can usually sell it for what you paid for it.
Or you can buy one of the inferior CD players you mentioned above.
The Music Hall is better than the Jolida IMHO. I own both. The Jolida does respond well to tube rolling should you decide to go that way. The best tube I found were original NOS CV military type issue 12AX7 Mullards. Before the tube roll it sounded dreadfully sluggish and muddy believe it or not.
What sounds good is a matter of personal preference and past experience. I'm having qualms about the Music Hall. Just read that the Phillips transport in a Shanling CDP (MH and Shanling
are cousins) is dreadfully slow, and there is talk of upgrading, as if it's not quite right out of the box.
While have I not listened to the specific Cambridge Audio models you have listed, I did own the original 640 and the version 2 and for the money they were excellent single disc players. In fact I preferred them to the comparable NAD models at that time with the exception that I have a fairly large collection of HDCDs and certain NAD models provided HDCD decoding. But head to head on a regular CD I liked the Cambridge Audio.
The Esound CD-E5 is better than the Jolida. I had a Jolida with upgraded tubes. I am considering selling mine not because I don't love it, but I am going the HTPC route and need a dac. Not sure what would better or equal the Esound for the money.
There is no single "best" new player in your price range. They're all going to have certain strong points and weak points. And, they're all going to sound slightly different, from one another, depending on who you ask. Unless you can demo and compare sound for yourself, you might as well just pick a number from a hat and go with it. Or, compare things like warranty duration, available service facilities, styling, ergonomics of remote, so on and so forth.
I just demoed the NAD C545BEE and Marantz 5003. Both are nice. I thought the NAD sounded fuller and more dynamic. The Marantz seems sturdier, but not as fun to listen to.

I owned the Music Hall cd25.2 and Cambridge 540C (ver. 2). The MH is very nice: super quiet transport, nice build, transparent sound. I liked the sound of the Cambridge 540, too, but at low volume I could hear the disk spinning from across the room.

Haven't heard the NAD 515 or Cambridge 340.
Should have added that my Music Hall wouldn't play a lot of home-burned cds. No problem with the CA, and the NAD and Marantz are supposed to work well, too (but I don't have first-hand experience with them).
Check out the Yamaha DV-1800. It does SACD & DVD-Audio and can be had on Amazon for $79.99. It listed for $449 back in '07.
Spot an Arcam Alpha 8 or an Alpha 9. These are very good players that can be had for a 1/4 of what they were. They are a bit older now but will still stand up to anything else in the price range.
I am looking for the same, I want to remplace my NAD C525Bee. Nothing wrong with the player, very good for the money but wish to find something better out there, my main goal is to find a player that puts this analog touch to music, i know some might say, hey buy a turtable.
Not sure if is possible to get something good in the used market with such a low budget but i have read good reviews for Marantz, Sony and Rotel. But I will go for some japanese brand, i found them more realiable. I do not trust small boutique manufacturers (not so many in this price range though). They might sound good but they dont last. I like that sony and marantz are SACD wich is nice thing. There is also a nice New Onkyo for $ 300 something but I did not try it.