Climate control depends a bit on where you live and how well insulated your shop is. I can work in the heat if needed, but hate the cold (Midwest, we get plenty of both) so I have a good electric heater.
A sink is great, don't need a toilet, but my shop/garage has always been attached to the house, so no big deal.
Don't have any interest in a TV, don't need beer in the shop, beer is for after, a small fridge with cold drinks is nice, but zi can bring a large 32 oz. cup filled with ice water or tea or whatever, and that will get me through most of the day.
Seating when you can or it makes sense helps the back.
I like light when I need it, and I need more as I get older, but when I don't a little dim is much more relaxing than glaring light all the time. I have motion lights to give me a minimal level of light instantly if I need to go in the garage and grab something.
Clutter/organization. I used to have a really good memory, didn't need to be organized because I remembered where everything was. As my tool collection has grown and my memory has shrunk, I find organization more important, but I make a godawful mess when working on a project, the focus is on completing the task and everything else is secondary. Clean up comes after.
That said, a good sized trash can in the garage is very helpful.
Phone and a quality Bluetooth speaker gives me all the sound/entertainment I need.
Plenty of workbench space, plenty of accessible power outlets.
Mostly covering already covered ground here. I will add that one thing I don't have room for that I would like is an old comfy chair. If I am knee deep in an all day project and pretty grungy all over, would be nice to have a place to sit down, eat, and relax for a minute without worrying about getting it dirty.