I'm looking for a single pedal looper with just the basic functions... I just want to play chords and solo over them. The boss RC-3 looks good but pricey. I'm thinking about the Tc Electronic Ditto looper.
Digitech JamMan Express XT.

Same as the ditto looper + bigger, stereo and with a status led.
Also cheaper.
I vote the Ditto because I own one and personally love it. I've never tried any other loopers and I have no desire to do so.

And contrary to what the person above said, they are the same price.
Love my Ditto, but if the local GC would have had a JamMan in stock I would have bout it instead since it is cheaper. I think they are about the same. Not that the $10 or so really matters over the years you will have it.
Ditto the Ditto. It's the shit. The jamman is good, too, but the Ditto just feels better. The way it's triggered on the down stomp of the button, rather than when you release, makes it much more natural to just line up a riff and solo over it. The RC-3 is sweet, but way too complicated for what you want to do.
+1 to all of the above, just with an extra thought to throw out there:

Have you thought about getting a multi effects unit that includes a looper? You don't say what other kit you have, so if you don't already have something like that it will give you the looper you need, plus a lot more for you to experiment with.
From what you described get the Ditto. I have both the Ditto and the RC-3. The RC-3 is ok if you add the dual FS-5U pedals, if you don't you'll be hitting the pedal aimlessly trying to get it to do what you need.
No one responded to my thread earlier about a similar question, but I wanted to ask: TC Ditto or Ditto X2?
Correct me if I'm wrong, but the X2 adds effect in the pedal, but not much on the looper side?
You're right, but I was wondering if the mechanics of the loop are better/easier to use/different
The X2 looper is essentially the same as the small Ditto, but with the added loop effects (reverse loop and half time). Other than that, it also lets you use the FX button as a single stomp stop button if you're not using the effects, rather than having to do a quick double stomp on the button to stop. It also gives you stereo in and out, lets you load loops from your computer, and comes with free JamTrackCentral backing tracks.