I've tried to get 1st place on the 150cc Lightning Cup no less than a dozen times without success. Stupid Toad just rocks me every time. The Grand Prix game mode on 150cc just feels like a 1 vs. 11 team mode. One time I even got first place on each of the first three races, only to take 11th place in the last race and lose to Toad by 3 points. Ugh.
I think I'm just bad at Mario Kart. I have been having a lot of fun with the time trials. I enjoy that game mode more since you just compete against a ghost and there are no items to deal with. It's a more pure driving mode, and that's what's really fun about the game, stringing together a huge set of drifts, hitting the perfect line, jumping over obstacles and doing tricks.
I'm going to be a sucker for Gran Turismo 5 when the full version finally releases. I hope it has aerial tricks, too.