Distinction between remake and re-release.
Re-releases would be things like Conkers on Xbox, it was basically a straight port of the N64 code and tweaked up the quality (not by much I might add). Same with the upcoming Perfect Dark for XBLA, yeah, it has been improved a hell of a lot graphically but it's not a remake.
others I'd include are:
-God of War Collection
-Street fighter 2, HD Remix
-Banjo Kazooie
-Banjo Tooie (god damn it Rare, can you make a good new game rather than JUST re-release your classics?)
-Earthworm Jim HD
A few new textures, features and resolution-bump doesn't quite fit the "remake" definition.
Now REMAKES would be something like Resident Evil (2002) where they really just did the whole thing over again, they literally made it again, starting from scratch.
Doom 3 (to spite the number suffix indicating a sequel) is effectively a remake of the original 1992 Doom but switch out run-and-gun for survival-horror. The recent Aliens verses Predator, a remake in my book, it's sure not a sequel to any of the other AvP games. All of these are at least decent, and at the very least they remind you of the original that you may be more likely to visit.
One of my favourite has to be Tomb Raider Anniversary, one thing I love about that is how each game has their own qualities and overall I like each equally for what they do, Tomb Raider 1 is just soooo 90's.
I think the key to a good remake is remind of the old... but mix things up a bit to keep it fresh and ideally it will make someone who plays and loves the remake go back to play the original.
But I also appreciate re-releases, I missed banjo-kazooie when it came out, I also LOVED Perfect Dark, my N64 is long gone and I'd love to return to it with new controls, graphics upgrade and *nerd-gasm* online multiplayer... (AW CRAP, I just realised I need to buy XBL Gold membership). Still, re-release are win to me because it makes for a great retrospective, its strange that it is so easy to go back and watch a film from 1997, yet doing the same for a game is so hard.