Luigi's Mansion is based on the Mario universe, and i guess 'could' be considered a 'Mario' game, but the gameplay is very different, and really nothing like anything ive ever played. I find it a really great game, although its short, its really fun and doesnt get boring.
Wario World is more a... Wario game if you know what i mean, doesnt have Mario in it. It's classic platforming though, 3D and 2D mixed together, and also a very fun game, although short like Luigi's Mansion. They are both single player games, nothing like Mario Party.