I've got three DVD capable devices hooked to our TV (Xbox, Mac Mini, DVD player). I keep the DVD player around as it's the only one that's region switchable. Haven't made the jump to blueray yet as it means upgrading the TV first. I really can't wait for our TV to break.
I have a HD tv and use my PS3 to play DVDs. Don't have any blu-rays yet, but that could change when they become more prominent.
We just dumped our DVD player for a Blu-Ray player. The biggest reason was that the Blu-Ray player doubles as a network box for bringing streaming Netflix movies to our TV. Better (and cheaper) than On-Demand Pay-Per-View. I did buy Star Trek on Blu-Ray and it's beautiful in HD
My first was Chronos, an IMAX film. It's my favorite IMAX film ever. I got its Blu-Ray before I got a player to run it on. I just knew I wanted that disc. And it's one of the most beautiful Blu-Rays I have ever owned. You'd never know that the film is over 20 years old, it looks brand new.
I was joking, in case anyone couldn't tell. I don't think Revenge of the Nerds is even on Blu-ray. I can't even remember what my first Blu-ray was. I guess it would be Ricky Bobby by default since it came with the PS3, but otherwise it might've been Black Hawk Down and The Prestige.