Alpha Flight was on the surface a diverse team and with similarities to the Titans, but lacked a bit in terms of their mid-level members.
Guardian/Vindicator: flight, force field, energy projection
Sasquatch: Super Strength
Shaman: Magic
Snowbird: Shape-shifter
Northstar and Aurora: Super speed, light generation
Once you got past Sasquatch and Guardian, the rest of the team weren't all that much.
Puck and Marrina didn't really add much more to the team in terms of capabilities unless you desperately needed to express deliver something to Atlantis.
The early Exiles and Thunderbolts teams were among my favorites.
Exiles
Mimic: rotating power set of any 5 characters (at about half their original power level) flight, agility, strength, optic blasts, bone claws, regeneration
Magnus (died too early really to be considered)
Blink: teleporter, agility
Morph: Shape-Shifter
Nocturne: Agility, Body possession
Thunderbird: Super Strength
Sunfire: flight, flame generation
Thunderbolts
Citizen V: leadership, swordsmanship
Mach 1: flight, body armor
Songbird: Solid sound manipulation; flight
Atlas: Super strength; growth
Techno: Technology expert
Meteroite: Strength; flight, energy manipulation, phasing