LOL, this is ask at least 5 times a day.
Wii MotionPlus is required for Wii Sports resort. Everyone that wants to keep playing all the latest Wii games needs to understand that they are going to need to get the M+. Most if not all future Nintendo made Wii games are going to require M+. The new Zelda is confirmed M+ only as is Red Steal 2.
Once you try it you won't have any trouble wanting one for all your controllers. There are two game out now that are sold with M+ for an extra $10, Tiger Woods 10 and Grand Slam tennis. Wii sports resort will come with one and so will Red steal 2.
I have Tiger Woods 10 and Grand Slam tennis and once I played these games with and without M+ I went and bought 2 more Wii MotionPlus attachments. The new level of control is unbelievable, I hope all games, Nintendo and 3rd party require it in the future.
Playing a game without is like flying a paper airplane and playing a game with M+ is like flying a real airplane. That is the difference in control. I would NEVER play a game that could use M+ without it and once you try it you'll never want to either.