Just bought a Archos 605 Wifi 4GB for $135. Added the $20 codec to allow it to play raw Replay MPEGs, and I couldn't be happier.
My wife had come home with a Memorex 8GB MP3 player from Target ($99), with a smallish (2.4"?) screen, and asked if it could play Replay files. After doing a little research, I found it probably could, but that they would most likely need to be converted first. After doing some research on anythingbutipod.com
I decided on the Archos, and to have her take the Memorex back. It has a large 4.3" (800x480) touch screen, and it accepts SD cards (including the large 16and 32GB SDHC cards) for easy expandability.
The device can play DIVX AVI files too (typically 700MB for a 90 minute movie), which are even smaller than the standard quality Replay MPEG's, which is an added bonus for those into downloading Torrents.
I'm planning on grabbing one or two 16GB SD cards from Staples tomorrow, they are on sale for $35 (this size is the sweet spot for price/capacity IMO). Later in the year 64GB SDHC cards will be out which will be nice.
The wifi is handy too, I can stream/transfer video and music over my home network from my Windows Vista PC, or of course plug it into the computer (USB) to transfer files to it. You can pay another $30 to unlock it's web browser, and there is also a dock that allows you to use it as a DVR, in addition to other accessories. It looks like DishTV users can also download a free plug-in to allow them to transfer files from their DVR to the unit.
The user interface is well thought out and quite intuitive, and there are little touches like a fold out arm to allow it to prop up and watch it hands free which add to it's usability.
So, I have a 20GB (expandable) wifi PMP with a great interface for about $190. A similar iPod Touch with 16Gb costs would have cost me about $100 more, and would have a smaller screen with lower resolution, a little less memory, and no expandability, though it would be able to surf the web out of the box, which would cost me $30 more if I wanted that feature.