The trouble with Star Trek's holodecks is that they kept going wrong or were hijacked by aliens and became a threat to the ship. Frankly with that kind of record they would be switched off and locked in real life. But I suppose the holodeck was simply a vehicle to go off on some tangental storyline.
The one episode I particularly liked was in 'Voyager' when the had to act out an entire episode of some 1930's Flash Gordon style 'folly upper' as they called them there. Captain Janeway as the the 'Spider Queen'. It was a hoot.
As for my holodeck fantasy. I liked Thrawn's suggestion combining the best of all feel good vacations.
I imagine if there was a real holodeck. There would be pre-programmed games like we have now. Adult games would cause huge controversary and probably be as rubbish as any porn video. Let's be honest is there any such thing as a PC sex game?
Concerned parents would claim they are corrupting their children. The religious right would try to ban it. Ambitious politicians would condemn it and the media would sensationalise it.
You couldn't use real people because they would sue your ass:( You might be able to get home made holos stolen from say, Pamela Anderson or Paris Hilton.
There would have to be huge safeguards, 'safety protocols' as they call them in Star Trek. If anyone as much as sprained a finger while re-enacting the Battle of Gettysburg. The manufacturer would be sued.

Heavy users would get holo syndrome or 'holohead'. Doctors would warn about restricting use to a few hours a week. The police would complain the criminals were using to rehearse crimes. Murderers would claim that they lost touch with reality and thought they were still in a holodeck or were inspired by a holodeck program.
I think it would be just like we have now. There would be some holos made like movies. The difference is that you would be in it. Maybe taking part or just watching as if you were invisible. Others like games, first person shooters and simulators. There would be educational holos and of course the military would use it for training. Historians would re-enact historical battles and then argue about the authenticity of the programming.
Oh yes, the technology changes but people don 't.
So I think you would use it the way you would use a PC or games console now. In my case first person shooter, simulators and of course AH27.9 holo download. (Only 3779 gigs and a mere $15,000 a month).
I doubt it will happen soon. But we had something similar not long ago. Whatever happened to virtual reality. That was the next big thing several years ago. Where did it disappear to? It's gone like a holo character outside the holodeck
But there is one holo experience, I would like to experience.It's a grass airfield on a sunny day with fluffy clouds and the lark singing overhead. My choice of aircraft lined up before me ready for me to fly. Only a few other people will be there on the airfield. All attractive women wearing only a silk scarf ready to swing my prop. aaaaaaaaawwww:aok