The most useless skill

Firemaking - Unlike construction, there's no way to show off this skill, nor is there a purpose to it.

"Hey look, I can burn this magic log in 3 game ticks!". "No way?!"

Come to think of it, crafting's pretty useless too. At 90 there's Furies, but how often do you get an Onyx gem, the skillcape's quite ugly and the only purpose it really has at a decent level is Dungeoneering.

I would say firemaking but it gives that adze which is worth it. Many of the buyables don't really a use either. Cook isn't useful, fletching isn't, smithing isn't but it has a nice cape.

Firemaking by far

Gonna have to go with Firemaking (even if it was my first 99 )

i would say smithing - but fagex are apparently bringing out untradeable armour like overloads.

I really hate theif :c

Firemaking is rather useless although I guess there is the inferno adze which makes it worth raising to 92. Other than that though, I really can't think of any good uses for it.
Thieving is another one. It's a fast skill, but again I can't think of many good uses for it. Hopefully that'll change if Jagex decides to update skills to make them more worthwhile to train. That would also motivate more people to train skills which are currently seen as being useless.

gotta go with firemaking

Firemaking/Thieving

It's surprising that thieving has such little use, apart from quests, because it seems like there SHOULD be loads of uses for it... but at the end of the day.....firemaking...just wow