The ONLY choice (under $400) is the TC Electronics M-ONExl. I had the Lexicon PCM81 and 91 and for 2 grand(each), they were great. In a more budget minded setup - the Lexicon MPX500 is pretty good, but sounded more mettalic than the TC. Older M-ONE's are being blown out, but the XL model has more stuff, and a few more advantages.
There are a lot of adequate reverbs for $200, but the M-ONE gives the best impression of an expensive unit that I've ever seen. (or HEARD)
Forget about the lower end units, for a little extra, the TC will make you forget the expensive Lexicons of yesterday.