I am getting ready for the final battle. My Shepard is an Level 60 Adept. I am in the final preparation steps: that is armor selection, best bonus power, weapons upgrades and squad selection. I was planning on using:
Armor: Inferno Armor
Bonus Power: Slam (right now it is Energy Drain)
Weapons: ?
Squad: Liara (My LI), and Tali or Javik
I would like to know what the community thinks. I know that some of this is subjective.
You are set.
As far as Energy Drain, there are two enemies in Priority Earth you can use it against. Whether or not it will be worth it will depend. Marauders are fairly common, Banshees not quite as much. But for the most part shields / barriers aren't as common in any of the missions in ME3 as they would be on ME2 Insanity to begin with. How often did you end up using it in other missions? You could save it for strictly defense.
Personally I like pure characters, so I don't run tech on biotics. Slam is a fine power on an Adept, the main knock would be that it has a bit of overlap with Pull. Honestly by Level 60 the vanilla Adept powers cover practically any situation so you could consider something like Warp Ammo for extra damage, or go defensive with Barrier or Fortification (the latter is actually slightly better after the last patch). The recharge penalty from either is small by late game, especially if you are taking an optimized weapon loadout.
As far as squad is concerned, Liara is probably overall the most powerful squadmate in the game given that her cooldowns are so low when appropriately leveled, and her Singularity is hitscan and hits instantly, unlike Shepard's. Javik is also good, and the Liara - Javik squad is one of the most powerful combinations in the game for any class, and of course works well with Adept.
Tali, on the other hand, is one of the least useful squadmembers. She peaks in usefulness during the Rannoch arc and is really best against synthetics. The small caveat would be if Shepard is tech and you want to use Tali to spam Sabatage and apply "Tech Vulnerability" debuff before Shepard and the other squad member hit them with tech powers.
If you want to chain combo types you could consider EDI. Then you could combo larger targets, like Brutes, in the following manner:
EDI Incinerate -> Liara Warp -> Shep Throw.
That will give you a fire explosion and then a biotic explosion. Against Barrier, EDI would use Overload. Garrus can also help with chains, but only via tech bursts. If you brought him it would make sense to have Proximity Mine leveled to at least Rank 5 for Damage Taken debuff to help damage the high hp enemies more rapidly.
Weapon choice is completely subjective as there are a lot of very good weapons, so what you take will depend on which ones you have acquired and leveled up, which in turn depends on DLC. The most powerful per weight overall are Arc Pistol, Suppressor, Wraith, Venom, Harrier, Punisher, and Lancer.