No True Star Trek Fan would fail this test

Easy.

If this gif wasn't in here I was gonna be upset!
I've considered growing a goatee and using stick on mutton chops to cosplay Thomas Riker at conventions.
- I was waiting for this GIF too
  If I ever see a Riker cosplayer ... I'll try removing their mutton chops .... (I'm joking, I'd never touch anyone's face for any reason)
When this episode first aired I was like ohhhhh snap!

Pfft easy.
Ones Thomas, the other one is Will.

The one pictured above is Will, and the one pictured next to him is Thomas, it's easy really
- That's what i said!
A real true fan would see at the first glance it's the same picture posted twice. But are they of Thomas or of Will?
- I count 3 pips.
  Thomas had the life altering experience of having to think of what he wants out of life and desiring personal happiness and relationships, so this is Will.
- Shrodingers Riker
You failed the text. That one is Will, its the other one that is Tom.

Easy. Thomas is the exact same action figure but painted yellow, with the little tears on the uniform moulded into the figure still visible.

(Me, still bitter that I held this figure in Woolworth’s and passed on it because it was a shitty repaint)

The one that rips off his sideburns is Thomas

Trick question.

Those are actually transporter twins #6 and #14, Darcy and Coltrane.

One married Troi the other didn't

Two Rikers at the same time. If I ever become a trillionaire, that's what I'm doing.
Lucky dog!

Luckily he was a different rank so they were never dressed the same.

Thomas wore commander pips and command red when he stole the Defiant.
- But we know this isn’t from that time.
  The galaxy was going through a blurry low pixel phase when that happened, and this photo is crisp.
- Yeah but that's because he was pretending. When he's not pretending he dresses like the gold shirt leftenant he is
Luckily he was a different rank so they were never dressed the same.
Ooohhh, you just failed the Star Trek test. Do you even DS9, bro? /s

Will always has a trombone on him at all times. It's why he sits like

Thomas is the one with stick-on sideburns.

Easy, Will is the one drowning in pussy.

It's the trauma, isn't it?

Simple. Thomas uses too much tongue.

I mean, it's pretty obvious that the one on the left is.

That's our starship, comrade

Thomas is the one in a Cardassian prison. I wonder how he's doing.

In my headcanon Tom was rotting in a Cardassian prison cell when Cardassia finally turned on the Dominion on Cardassia Prime. A trained Star Fleet lieutenant is a powerful asset in a battle. Seeing the Dominion as a worse threat to the Maquis interests than Cardassia, Tom convinced his jailers to free him in exchange for him fighting to defend Cardassia. The combined Alpha Quadrant forces succeeded in defeating the Dominion. While Cardassians would have wanted to re-imprison Tom, the destruction and chaos was too great and Tom was able to slip away and make his way back to a rim colony that supported the Maquis.
The colonists, aware of the sacrifices Tom made to defend them hid and housed him. These colonies were far off the radar of the Federation at this point, so there was no one in power caring what they did, including if the Federation discovered Tom's whereabouts there. Tom had everything he could build a happy life with there, and a community that loved him. He could have lived there happily for the rest of his life...but that's just not the temperament of a Riker, so he left the safety and comfort of that work and once again threw himself into the fire for a cause..
...but that is another story.
The Federation got him out during the Dominion War and made him a captain according to the games. He's free in canon too. His name was on a list of Starfleet officers being taken into protective custody on an episode of Lower Decks.

It's the lil pasties

Thomas never wore that grey-shouldered uniform though.

One got promoted to Commander, the other didn't.

The right one has more lines on his forehead, considering Thomas spent time on that isolated planet, it has to be him. Hard to frown when you're killing it on trumpet on the flagship of starfleet.