Into Musical Theatre

A Flamboyant Gay, who lives for acting, singing, or performing in general. They love the spotlight, have memorized every line from their favorite musicals, took modern dance or ballet at some point, and are constantly trying to break into theater. The female variety is invariably straight, but unlike the male version, stands a good chance of also being a Soapbox Sadie.

Well enough known that the expression "he's into musical theater" is a well-known euphemism for being "gay".

Anime and Manga

 * Nathan from Blood Plus lives for the stage and is the producer/manager/whatever of Diva's musical debut. Of course, the performance he most wants to direct and present to an adoring audience is Saya's death at Diva's hands. God help you if you try to screw it up by doing something silly like killing Saya before he sets the perfect stage for her and Diva. Lights, camera, action!

Film

 * The entire cast male of the movie Camp, aside from Valentine.
 * The Producers had a whole crew of these, led by Roger DeBris.
 * Ryan Evans from the High School Musical movies.

Literature

 * Tiny Cooper in Will Grayson Will Grayson by John Green and David Levithan. Even to the point where one of the books major subplots is the direction/casting of the musical he wrote about himself.
 * Annie in Annie on My Mind is a rare female version of this trope, being a keen and talented singer with a passion for the dramatic.

Live Action TV

 * Jack of Will and Grace.
 * Kurt from Glee.
 * Blaine, too.
 * Maxxie from Skins

Video Games

 * Sander Cohen from BioShock (series) can be triangulated at the center of Performance Artist, Mad Artist, and Depraved Homosexual.

Web Original

 * Apollo from O-Cast. He is the god of music and poetry, after all.

Web Comics

 * Almost the entire cast of My Life in Blue.

Western Animation

 * Bruce from Family Guy.
 * Squidward from SpongeBob SquarePants. Granted he's pretty straight, but he is on SpongeBob SquarePants.
 * The lisp-spouting, male actor worshiping, drama teacher Mr. Bickles on The Fairly OddParents.
 * Mr. Fleur from Cow and Chicken.

Real Life

 * Neil Patrick Harris