I haven't stayed at many of these brands, but I thought it might be worthwhile to compile typical amenities of hotel gyms.
Hampton Inn - Not all have fitness rooms. Those that do have a treadmill, elliptical, and bike. There may be a universal machine and occasionally free weights. Older hotels often have older equipment.
Hilton Garden Inn
Hilton Grand Vacations
..more to come after dinner
Please comment about the fitness rooms and I'll update up here. I'll try to keep this post about usual fitness equipment or offerings. Special hotels can be discussed in the comments.
I'm not sure you can break it out by brand so much as by specific hotel. I've been to dif hotels of the same brand & their fitness rooms are different, usually based on age of hotel, location, type of hotel, etc.
BTW - LOL - when I read the title, I thought you meant like what was in the washroom or showers if they had them in the fitness rooms, such as Bvlgari, Crabtree&Evelyn
Yeah, I think you really have to look at each individual location.
I've stayed at Hiltons with very small fitness rooms and I've stayed at a Hilton like the one in Anaheim with a full service gym located inside.
Embassy Suites heavily advertises that they have Precor fitness equipment. The ones I've stayed at always have had several treadmills, ellipticals, and a bike or two. Usually I also find weights, mats, and balls.