Yep, Waverace is essential! Not sure after that as I haven't really bothered with VC games TBH.
I would have recommended Super Mario World being one of my old school faves but you do NEED the classic controller for that one. I don't have a classic controller & although it plays with a standard Gamecube controller(or Wavebird in my case), the lack of button reconfiguration makes the constant running + jumping an almost impossible task
You'd need either the classic controller or a gamecube controller/wavebird.
As for type of game, out & out arcade racer on waves. The Jet Skis are great fun to race & control superbly with the rolling waves, the graphics even hold up very well since there hasn't been much to compete with it since originally released.
Have a little look around this site http://www.vc-reviews.com/ great for VC game reviews & they should have all of them covered there
It depends on your gaming back ground and if you don't mind playing retro games.. I love the VC and in my opinion there are some right corkers to look out for.. The N64 games are obviously the most modern and probably the easier for newbies to get into..
My recommendations are as follows:
F-Zero X - Futuristic racer ( similar to Wipe-out but with out weapons )
Lylat Wars - Space age shoot-em up
Mario Kart 64 ( racer with karts )
Paper Maro 64 - RPG/Adventure
Super Mario 64 ( 3D Platform )
Legend of Zelda - Ocarina of Time ( one of the greatest adventure games ever )
Wave Race 64 ( awesome )
N64 games are 1000 points
If you don't mind going for even older games then i recommend the following:
The Legend of Zelda: A Link To The Past ( Adventure - Superb and again one of the greatest games ever )
Super Probotector ( Platform shooter )
Super Mario World ( Platform ) Also excellent !
Street Fighter 2 Turbo ( beat-em up )
SNES games are 800 points..
I've not much experience with Mega Drive games or the others, so maybe others could chip in on their recommendations..