Get one legacy moveset for free
lets just imagine you have 2x lagacy tms. One for fastmoves and one for charge moves. In which Pokémon one or two would you use them?
My choice would be rockthrow rockslide omastar
Answers
Hmm... does this hypothetical Legacy Charge TM following the normal charge TM randomness? If so, Dragonite is a bit of a gamble between Dragon Claw and Dragon Pulse.
I do have a Dragon Tail/Dragon Claw and a Dragon Tail/Dragon Pulse both with good IVs, and a wild caught Dragon Breath/Dragon Pulse with bad IVs, so any of those could be a candidate. I regularly use the DT/DC, so I might want to keep that.
If I have only one Legacy Fast TM though, the only hesitation against using it on Dragonite would be if I could get Zapdos with Thundershock.
For the sake of rarity, Psybeam chansey or Stone Edge Blaziken. Neither of which have a practical use (yes they cover some weaknesses of each) but for the sake of collecting, I envy those that were fortunate enough to obtain a chansey with psybeam (or rock throw omastar, mud shot golem, etc.) during the first 6 months of the game, especially since obtaining less common pokemon was particularly difficult during the initial release of the game