I have to say, no matter what, I'm sticking with pinside. Not even just from a forum standpoint.
-It's the best database for solid state machines (and it's linked to ipdb if you fancy an EM machine).
-Its the best top pinballs list online.
-It has the average prices listed.
-The reviews are great quality and the stories make good reading material.
-It's my favourite place to check the pinball market.
-Oh and did I forget to mention, IT'S THE BEST LOOKING PINBALL WEBSITE EVER.