I have two unused character boosts (110 and 120) and don't know what to do with them

It depends on player to player tbh.

On my case I used my Legion boost on a second Hunter, a BE one, since I didn’t want to spend money race/name changing this one.

My BFA boost was spent on a BE mage after I made her as a trial character.
Because I didn’t had a mage and I wanted a BE cloth character.

I have no regrets.

I keep playing them along other 8 characters, including this one.

My 8 remaining characters are:

  • 2 Warriors
  • 1 Paladin
  • 1 Monk
  • 1 Priest
  • 1 DH
  • 1 Rogue

I still need to hit max level with:

  • 1 DK
  • 1 Shaman
  • 1 Druid

I need to start playing a Warlock.

As you can see, what’s technically fun, is subjective from player to player.
I consider Hunters fun and Warriors afterwards.

Off topic:
RNG makes me feel happy I have 2 Hunters.
See the amount of 445 TW gear this Hunter has ?
She has another set of Azerite gear ILV 445, for a second off-spec.

My BE got 4 MM boots, 2 Duplicate BM rings (1 slotted). Basically a disaster.
Even running LFR, I got only one Azerite shoulder piece ILV 430 and the Helmet ILV 430, I got was donated by a generous Orc Hunter.

Thank you kind soul wherever you are.

Meanwhile I have no off-spec Azerite gear.
It’s even worst if we consider the countless Heroics she’s been through before TW and LFR. Also the amount of extra TW chests she has opened in comparison to this character.
All of my 9 characters have some duplicate Azerite gear 415, 430 or 445.

This one has about 77 days between Vanilla and TBC.
But my BE Hunter is the one that has more game play time between Legion where she was my main and BFA.

I am starting to noticing, that the character I play the most is the one that gets screwed the most in RNG …

Edit: typing.

Cheers.