Ultimately, if you really want to find out what happened in RE2 and Code Veronica, you're best off getting copies the originals and playing those instead. They're on multiple systems (and potentially may show up on the Wii if Capcom's Resident Evil Archives series continues) so there shouldn't be much trouble finding them.
As expected, the originals are better and more authentic Resident Evil experiences, and you'll get more enjoyment-- though not multiplayer-- out of them. Darkside Chronicles, on the other hand, is best for someone who absolutely loves light-gun games and has a buddy along for the ride.
7/10