Mario is Missing is the only game I have ever returned due to "badness". I beat it in 2 days when i was about 7 (when did that game come out?)
SMB2 is ok, but Tetris Attack RULES!!!!!
Yes, it was taken from a Japanese game called Paneru de Pon, and I wouldn't be caught dead playing it, as I am not really into "girly games". This is the only game i would avoid up to today due to graphics alone. Sticking the Yoshi's Island characters into the addicting puzzle game was a great decision on Nintendo's part.... And adding Pokemon got the younger people playing it, but i don't see why the Yoshi's Island characters won't do the job as well...
Anyway, take it from someone who can beat Very hard mode without losing even once 70-80% of the time, even after not having played it for about a year (it isn't as hard as you think, Bowser on Very Hard normally throws a x9 or so chain at you, but he leaves one column perilously stacked really high, so even a x4 or x5 chain stacks him to the top, and if you play with the BALL code activated, you easily win in roughly 10-20 seconds. If you let the match drag on for more than 1 minute though, you are generally sunk.): it is a great game! get it. Trust me, the ending is nothing special, but beat hard or very hard without losing and using the same non-Yoshi character for all 4 fights in the Cave of Wickedness and the ending will change slightly... I use Gargantua Blargg for some reason... the ARRRRGH noise he makes is really cool, in my opinion.
SUMMARY OF THIS UNECCESARILY LONG POST: Mario Is Missing is the "worsest" (sorry) Mario game, and any of you who hate on Tetris Attack are hating on my favorite game of all time. yes, it is my favorite game of all time. You may not think so, but I do.
*My real signature went on strike, said something about "unfair working conditions". So, this is a temporary replacement sig, until I can work things out with the real sig.