So I has a Wii Fit.
Like any good trainer, it insults you a lot and holds you to an impossible standard. That's fine. My main problem with it - which became my main problem with Brain Age after a while - is that there is too much shit to do. Variety is nice, but there's no indication that you're not somehow expected to do all 40 activities every day. There's no actual personal trainer that tells you, "Okay, you suck at lower body balance and not being really fat, so today we're going to do some aerobic and yoga shit." The damn thing itself actually yells at you if you use it for more than a half hour, so you'd think they'd bother to add in some sort of filtering algorithm to optimize your time. The best you get is a favorites list, which now believes that Tightrope Walk is the best exercise ever because I find it hilarious to vault myself into oblivion.
Also, the Fake Personal Trainer is at once sexy and terrifying. Not just because she's made of white plastic and speaks without ever moving her mouth, but because if you leave her alone for 10 minutes she'll show up again with her hair suddenly grown out three times in length.