Hmm... It's interesting reading that 25 Most Under-Rated Games article over on Gamespy. I think that they must have just had a look at what I had on my shelf and written blurbs about it.

Persona series... Check.
Valkyrie Profile... Check.
No One Lives Forever... Check.
Rez... Check.

I think that, especially with the older console games, I have quite the collection of underrated games. That was the advantage of coming back to consoles near the end of the 32-bit era. I just printed off lists of what was the best and what I found interesting and hunted the games down. I didn't care if it was popular, just if it was good.