Cassidy and Vic can both use the rifle animation, which lets you give them the M72 gauss rifle. Level them up and clad them in power armor.
Same with Sulik, but he can only use the big pistol/smg animations, so gauss pistol and power armor, or a super sledge and save scrim when friendly fire splatters him.
Marcus is awesome but.... he cannoy equip armor, so once you reach higher level stuff like the enclave he suddenly becomes a liability.
Goris is nice too, but temporary, soon as the enclave raid V13 you lose him.
The Ghoul npc you pick up in Gecko is also decent if you can gear him up fast enough, but fragile.
Your husband/wife from the shotgun wedding are rather useless... but not as annoying as Myron.
Myron in power armor with a gauss pistol can slap tho, especially on charisma builds where you have a lot of companions, some of my level99 runs back in the day Id get 10Charisma and a full party and be able to rapidly shred the higher tier encounters around san fran.