Emperor Palpatine is probably the best with his combination of telepathy, Battle Meditation and Wormholes, as well as Essence Transfer as an insurance policy. Without plot-induced elements he's going to be hard to get rid of whilst being remotely able to contribute significant amounts to warfare.
On a lesser scale, the Dread Masters have fleet crippling powers and can spawn some sort of corrupt armies. That said, they're clearly a lot more vulnerable than the Emperor. There's also Naga Sadow, who can spawn endless illusory armies and essentially win any battle if he's not caught, and he can pull off supernovae as a last resort. Both are secondary to Sheev but would be satisfactory supporting Force users if the Emperor's not available. There's also Bastila I guess.
Revan (well, if we base it off the KotOR games) is supposed to be a brilliant tactician with incredible powers of foresight and is a lot more involved in actual combat. But he's far from the most compassionate, is pretty disregarding of life and he's something of a heretic. He would probably make a lot of strange or questionable decisions that he'd not bother making sure everyone understands. And he's a got a history of falling to the dark side, lol. Darth Revan may be his most desirable incarnation.
As straight up fighters, I would pick Anakin and Luke Skywalker above anyone else. Preferably, Anakin should come with Obi-Wan, since they work well together.
Darth Revan as a commander(fleet admiral), he would be able to deal with other powerful force users without confronting them. Aka, if he encountered Nihilus as Darth Revan, he simply would out play with tactics, and blast him into space, without having to confront him, would probably do this to any Powerful force user, if confronted in a space battle.
Sidious, as the 5 star general, as he is extremely efficient with Battle mediation of a Galactic scale, as well as amping force users etc. with his wormholes etc, he is the perfect, Supporting role.
On planet battles, I would choose, the likes of KF Anakin/Yoda/Exar kun, as they could annihlate armies single handedly.
For keeping order,I would have Valkorian, as he could simply telepathically dominate Millions/Billions of people who got out of hand. And dominating fleets(A superior version of the dread masters)
For army busting:
Palpatine and it's not even close - can basically solo most galactic militaries via Force storms + telepathy.
For taking out enemy Force users:
Luke Skywalker or Palpatine.
For leadership:
Revan for tactics, and/or Palpatine for battle meditation.
For long-term growth:
Anakin Skywalker given his potential.