Who else can I use all these TMs on? Already done the legendarys, ttars, champs etc.

Same problem here lol. Dunno how many more A-Exeggutors I'll get before the "event" ends but considering that it has become my auto-select's newest, favorite pick (and that it doesn't totally suck), I might just spend a few dozen TMs switching bullet seeds for dragon tails.

If you haven't already played the TM lottery on Mew, that's always a route to take if you've got TMs burning a hole in your bag.
I'm trying to keep a decent stockpile of both fast and charged TMs just in case we get another big moveset shakeup sometime down the line (most likely when Gen 4 drops).

Wish I shared your problem. Why not TM your top 100 (bar legacy moves).

If you have that many TMs, gym defence probably matters in your area. Ensure all your defenders have their best movesets.

Tyranitar CD, IF smackdown happens, that's a lot of charge TM to go through FireBlast and Crunch