Who works best as a student?

[Sandfall]

It will always be The New Mutants for me, I did not read most of their comics but they never disappointed when they crossed over to and with the major X-Men books.

[AdamFTF]

Ehhh, when I said “student” I meant “teenager”...

Oh, well pretty much everyone except Professor X can work as a teenager, though some set-ups could be a little weird (like a world where Kitty and Jubilee are the adults and everyone else is a teen). It really depends on how much of them you're going to use. I mean, I didn't think Cyclops or Forge could work as teens until X-Men Evolution and I didn't think Wolverine could until X-Campus. With someone like Wolverine, you have to shy away from the "I have a long history I can't remember" thing and more towards the idea of him being a troubled, abused young man rather than a troubled, abused old man.

[Ricochet Rita]

It will always be The New Mutants for me

Same here. I still feel them as my personal classmates.

[Harpsikord]

In outside media a spread like Evo had makes sense, though I would make it so that Storm is also a student still, like in Apocalypse. She works better being from the same generation as Jean and Scott.

It's really the idea of upper and lower classmen that make it work. We can still have focus on the core characters like Jean, Scott, and Ororo as the upper classmen while also being able to have fun with a younger class that is an assorted mix of student characters... who even in the comics barring the New Mutants are still incredibly close together in age anyway because of the sliding timescale. I mean, Jubilee and X-23 for instance are the exact same age, and then even the New Mutants are probably under half a decade older. So, consolidating them all into one singular idea of "lower class" makes a decently signficant amount of sense to me. And for characters who are related the age difference is negligible enough that it doesn't matter, and some of them could even be in the same grade. For instance, Husk and Icarus.

[CRaymond]

In outside media a spread like Evo had makes sense, though I would make it so that Storm is also a student still, like in Apocalypse. She works better being from the same generation as Jean and Scott.

I sorta agree, but I'd make Xavier's "first class" consist of Scott, Jean, Kurt, Ororo, and Hank. Wolverine is brought into the team. Hank leaves for post grad work, Peter Rasputin is brought in. Then I'd move it forward twenty years so they're all grown adults and involved as actual teachers and moonlight as secret agents.