I wouldn't waste a nickel on a reciever that didn't have PLII. IMO it's almost a bigger boon to HT than Dolby Digital. I have a lot of DVDs with older Pro Logic soundtracks that frankly sucked enough that I rarely watched them, but w/PLII they're like new movies. One example is "Sniper", with Tom Berenger. Via the original Prologic, this is a very flat and uninvolving soundtrack, but PLII opens it up to an amazing degree. I've watched that flick three times since I got PLII but had only watched it once in the previous 3 years or so.
I really love Denon recievers for HT, and have used a bunch of em. The new '03 series is a great deal, loaded with features and (to me) is the easiest to use. I guess the easiest to use is the one you're most familiar with!
Even the second from the bottom model, the 1603, has two component video inputs and S-Vid all around, which is a must if you have a very complex system. On a bigger TV (say 32" or bigger) component vid is noticeably better than S-vid, so switching of component inputs is nice. The Denons I've used are completely transparent in the vid dept with NTSC signals (can't confirm HD, sorry). If you are lucky enough to have the DVD player w/DVI output, you can then hook up games to both component inputs.
Err, or maybe your mom isn't big on videogames...
Forgot who you said it's for! Well, I still like the Denons. Five channel stereo is a big draw of the Denons for casual listening and those who aren't high end purists. Likewise, PLII sounds good enough for music that I often listen to CDs that way.
Truth be told there are many brands that will do a good job at that price range, especially if you're talking a non-enthusiast that just wants something nice that's easy to use.