Another on the Wiilight side. Rock on.

HardCore:

1. Super Smash Bros. Brawl
2. No More Heroes
3. The Legend Of Zelda: Twilight Princess
4. Super Mario Galaxy
5. Re4 Wii Edition
6. Sonic And The Secret Rings
7. Metroid Prime 3/Okami

Replace Metroid Prime 3 with Okami if you haven't played any of the MP games and don't want to spoil them, or replace RE4 with it if you've played it too many times. Zack & Wiki is good also, so it could make a good replacement for any of the above.

Casual:

1. Mario Kart Wii
2. Rayman Raving Rabbids 1 or 2 (many prefer the first over the second, it's your choice)
3. Mario & Sonic at the Olympic games/ Guitar Hero III

Core

Godfather- Blackhand
Geometry wars
House of the Dead 2&3
Metroid Prime 3
No More Heroes
Medal of Honor- Heroes 2
Fire Emblem

casual

Defend your castle!!(only 500 Wii points!)
Super Smash Bros( i know i know... its not "casual", but do to its ability to pick up and play, its in here for me)
Excitetruck

I'm still surprised at the number of people who believe that "casual" games exist.

casual:wario ware,rayman raving rabbits 1,2
core:SMG,SSBB,MKWii,MP3,RE4:Wii,NMH,MOH:H2

If you like online shooters, you can't beat Medalof Honor Heros2...

'Hardcore':
-Zelda: Twilight Princess
-Super Mario Galaxy
-Super Smash Bros. Brawl
-No More Heroes
-Resident Evil 4
-Zack & Wiki (it's really hardcore, although it may not look that way)
-Okami (it's supposed to be fantastic at least, haven't played it myself)

'Casual':
-Mario Kart Wii (terrific fun for the entire family :D)
-Wii Sports
-Wii Fit

Zack and Wiki and No More Heroes for sure + the Nintendo games for core and maybe RedSteel or RE4!!

for casual: Mario Kart, Wii Fit and Mario&Sonic

I was happy with Wii Sports and LoZ:TP for the first couple of months, do you really want to buy 10 games straight away?

I suppose I may as well list my games collection:

Battalion Wars 2
Endless Ocean
Excite Truck
Mario Kart Wii
Resident Evil 4:Wii
SSX Blur
Super Mario Galaxy
LoZ: Twilight Princess
Wii Play
Wii Sports
Zack & Wiki

-----

Key:
Core (not for beginners)
Crossover titles (great for everyone)
Bridging titles (good for getting none gamers into more core-like games)
Casual titles (casual through and through, usually lacking any depth of any kind, but are fun for a group of you)

Dependant titles (your view of the game depends on your approach to playing it, I view Endless Ocean as core)


I think that seperates things nicely, most gamers will be happy with any of the games except the purely casual ones, but if you plan on playing with friends and family a lot then a casual title isusually a great addition.

Casual - Wii Play
- Guitar Hero III: Legends Of Rock
- Mario Strikers Charged

Core - Super Mario Galaxy
- No More Heroes
- Super Smash Bros. Brawl
- Battalion Wars II