It probably wouldn’t be possible to fit out a gym with a range of equipment to satisfy the needs of every single person at any one time however it may be possible to get close to it.
It’s an area where a combination of available equipment and a highly experienced trainer would prove useful. The trainer can, to a degree, compensate for the lack of equipment but it still might not be quite what’s suited to your individual requirements in order to get the best result
Going in to a gym for the first time there always appears to be enough equipment but it’s not until you’ve done a couple of workouts that you realise there’s stuff missing or certainly not enough of something during peak hours. The peak hours are always a good test of a so called well equipped gym and truly experienced staff in combination.
The most used equipment would have to be the machines despite the fact the free weights, used with the proper technique, can give an equal, and sometimes, better result. Squat racks get a fair bit of use simply because it’s the best all round exercise for legs. The new rubber plates, mainly used for squats, that are now commonly used and are interesting as they are big plates but it’s deceiving because in actual fact they are very light. Some members like to use them because they give the visual impression they are lifting big but in reality it’s just a big hunk of rubber.
So between the cast iron and the rubber it’s whatever turns your crank. Still, if you need morale more than muscle then maybe the rubber is the way to go.
Multi-Use Cross Over Stands also play a big part in the gym. An up market machine can exercise pecs, delts, triceps, biceps, lats, back, and traps. However not all of the muscle contraction during full range of motion with these machine is as successful as building muscle with free weights but they do have the advantage of a quick ready to go system with the use of various quick to fit attachments. Free weights on their own, with knowledge and training, will allow you to exercise any muscle group and you can expect a good result.
Probably the best way to get all the gear you need would be to belong to more than one gym. You not only get access to a lot more gear, but also the advantage been able to get a greater variation of muscle movements due to the difference in the design set up of machines.