Be sure to visit Javik's quarters after the mission for a scene where that continues. While every single squad mate has some incredible dialogue to offer here, the combination of Liara and Javik is explosive in the best possible way and isn't to be missed. Priority: Thessia - taking Javik on this mission is an absolute must.Pairing Tali with one of her old ME1 friends feels particularly good. Javik is great here as he so often is, but it's nothing major, so take whoever you like.
You can easily identify a main mission in ME3 because it has 'Priority' in the title - though despite that term, the main missions aren't truly a priority as they never expire. Mass Effect 3 is split into two types of missions - main and side quests. Mass Effect 3: Best Squad choices for main quest Priority missions On this page, we offer some suggests for the best squads to take to ME3's missions. With that said, certain characters certainly have more to say that's interesting in certain missions - with that depending largely on if they have a stake in the events of that mission. You should always choose characters for the squad of each mission based on your preferences, both in terms of which have skills that mesh well with Commander Shepard's, but also in terms of who you like most on a personal level.
The answer, obviously, is deeply subjective. Mass Effect 3 brings together a slightly smaller squad of warriors to take the fight to the Reapers, but there's enough of them that you'll always be leaving some folks behind on the Normandy - which always begs the question - what's the best squad for each mission in ME3?