Some have imagined that, if the holodeck were real, most people would spend every waking minute screwing celebrities.
Probably so, but what other uses can you think of?
Here’s a few:
…and so forth…
I don’t think sex would be my main use of the holodeck.
I’m not saying I wouldn’t use it for that, but c’mon! I’m only one man. She’s the machine, not me!
I figure I would use it for story oriented RPGs. Spies, D&D. Superheroes. Basically, I’d use it as a replacement for TV and Movies. Kind of like an interactive movie…a movie with some sex!
Oh, it’d definitely be an awesome tool for writing fiction.
Dunno how a real holodeck would compete with the one already in my head, though. It can come up with some pretty twisted scenarios, to say the least. 
Huge banquets of calorie-free holofood!
How about science? A team of doctors could wander through your heart before (or during) surgery.
Practice dangerous procedures before doing it for real (I guess we should cut the red wire first.)
Super video phone.
Tourism. Visit Mars with no space suit. See the rain forest without mucking it up.
You mean David Lynch holomovies? That could be interesting.
Though personally, I’m waiting for “Call of Duty: Holodeck edition”
safe Extreme sports.
Free solo rock climbing
Sky diving, or like on Voyager orbit diving.
Skiing, snowboarding,
I think that the Holodeck would be a terrific tool for war games. Let’s face it: how realistically can you actually simulate Waterloo while viewing the field from an effective perspective hundreds of feet in the air? How can you know what it was like to command Napoleonic-era troops without experiencing the chaos on the ground, trying to keep at the center of the square as cannon-balls whistle past you and the crack of musketry drowns out your commands to your troops? It’s certainly what I’d use it for…
Ok, after Erotica Gallumbits.
Alternate history scenarios.
Program very detailed histories of major societal events into holodeck simulators, then go back and tweak a major/little detail, and watch new histories unfold from the perspective of an interested participant: Lincoln survives Wilkes Booth assassination attempt and re-elected to oversee Reconstruction; Goering succeeds Hitler and his senior staff at Rastenberg in 1944 after they are found dead by poison; a revived Khan Noonian Singh hijacks The Enterprise and forms an Augment Empire, etc.
Remote operation of probes or robot doubles. Imagine: You beam down a party of robots with Data’s impressive physique. Meanwhile, you send your real away team of trained officers to the holodeck wearing VR suits that control the robots. The holodeck, using information from the robots and the ship’s sensors recreates the environment at the beam down point. Voila. Instant disposable super-soldiers, and none of the moral qualms of making and using AIs like the actual Data.
Psychotherapeutic roleplay. Under Troi’s watchful eye, finally confront your late abusive mother.
Traps for intruders. “Say, Kang, didn’t we go down this hall before? And why are gangsters shooting at us?”
Mario Kart.
I’d probably use it for Pong.
Add me to the list of people that’d be playing video games.
How about programming in your favourite book, and then watching the plot unfold as one of the characters?
Same thing goes for films, really - I know within a minute of getting a holodeck i’d be Luke Skywalker-ing.
Non-sexual uses for the holodeck
Sorry… can’t think of any…
Hunting people. Cannabalism. Torturing people. Killing yourself (what’s it like to be electrocuted, guillotined, etc?).
Yeah, but then you’d have to hack into those darned safety protocols.
D&D! Of course! That’s way too easy.
Ship’s maintenance and repair, especially for the dangerous areas like the drive units. The ship simulates conditions in the various units on a gigantic scale, then the engineers can virtually fly around them, noting places where problems are occurring, or are likely to occur. Thinking about electron tunnelling is one thing, seeing it happen is another. The simulation could be of great predictive value.
You mean Eccentrica Gallumbits, right?
Endless Sherlock Holmes, at least until it goes berserk and Moriarty becomes real.
So, five minutes, then?
I play lots Super Karate Monkey Death Car, you bet.