There's over 400 moves in Pokemon, and 92 of them are TMs in addition to the 40 or so move tutors in Platinum. But they're overdue to change the TM list - probably as soon as the next generation - and there's a few moves that need more exposure either as a tutor or TM. Plus, a few moves that I wouldn't mind seeing introduced next time around.
First, the candidates for TM or Tutordom:
#1 with a bullet. If Stealth Rock is going to continue to be one of the most commonly available TMs in existence, it needs a check. Making Rapid Spin a common move (and hopefully with the same changes I suggested a few months back) gives Yanmega among others new life.
Rock is primarily a physical type, but there is no 100% accurate physical Rock move. Special Rock has two, and Power Gem is just powerful enough to be possibly useful (70 power, though ideally it would be +10) while picking on a defensive stat that tends to be lower overall for the ones that are weak to it. The only complaint is that a whole 2 Pokemon gets STAB on it (and it's bloody Corsola and Probopass) and the other Pokemon that use it have better things to do.
Although usually following "Yeah, I" it's not as if the flavour of the move prohibits it from being used. In the right hands (something slow and bulky, perhaps) it could provide a great deal of support to allow a switching Pokemon to survive a stray priority move. And it would put a certain pink whore out of a job.
75/95/20 with 50% chance of making successive hits more powerful? I'll take two. Problem is, it comes from Zangoose first and has to be bred, which gives it a learnset of approximately 8 and all of them have no room for it except comedy Sandshrew sets. This would more than likely be a tutor move, and if it can be, let's make sure it goes to Dunsparce for massive damage. (I'd use a Choice Scarf Crush Claw 'sparce in a heartbeat as long as I could breed one with Serene Grace).
Not just for the theme song for the Joystiq Podcast. Again, this move has a single-digit learnbase (9, yippie) and has so many effects (neuters Flying type and Levitate, makes things vulnerable to Spikes, etc) that bringing this in as a TM or tutor would throw the entire game into chaos. And again, we need to put the fat whore out of a job.
The only major problem this move has is 5 PP, otherwise it's a great counter to things such as Dragon Dance Pokemon provided you can survive a powered-up hit (good luck). Add this to something with Intimidate - or even Bibarel with Unaware? - and shove the Dances right back whence they came.
This one has the least odds of happening given that its current learnset is a mascot, Togekiss and a bunch of banned Pokemon. Clearly, they think it's powerful enough to have to hold it back dramatically. Still, if they insist on keeping Double Team in its current form a TM, they're way overdue to bring in a powerful move not affected by evasion mods. Yes, I remember Swift Dancing. I was there. It sucked.
And there's a few moves I'd like to see introduced next time around and used as TMs:
False Swipe with Extremespeed: A 80 power, low PP (15 prefered) Normal move that cannot faint. It's a dual purpose move: It makes catching this less of a pain in the rear, and lets you play some serious mind games in PvP. Speedswipe w/a priority move? Or how about with Whirlwind/Roar and an entry hazard?
Fighting Flamethrower: A 80-100 power physical Fighting move with 100 accuracy, 10-15 PP and no drawback (or a small odds of causing flinch). I went over this before, but the only 100 accuracy Fighting moves with decent power are the ones that lower TWO stats. I know the Fighting type is supposed to be all about power, but certainly something like Medicham (who's part Psychic) at the very least can figure out a way to hit unless evasion is in play without making itself vulnerable?
Breaking The Mold: A field effect move that neutralizes abilities for all Pokemon for 5 turns. There's moves that change abilities, suppress them, change them to Insomnia or let you copy them, but it'd be interesting to see what would happen when we can go back to RBY for a minute. (Only problem is: Use this move and all of a sudden Regifailure can switch in and start beating crap down for three turns before Slow Start kicks in. It'll blow you away [IGN.com]).