When it was released, Crash Team Racing > any Mario Kart.
Modnation Racers is criminally underrated. The load times are too long, but the gameplay is extremely satisfying and the customized karts you can get are great.
Media Molecule, not Bethesda, gets the biggest pass from gamers and the media. Their games have charm, but the way they get hyped and covered makes you think everything is revolutionary. Nothing they've made has wowed me.
Besides online infrastructure, Microsoft has brought nothing worthwhile to the gaming industry. We would be better off if Samsung or some other tech company got in the mix and MS bowed out.