There's also nothing stopping you from giving Boone the Gobi Sniper and watching him work. Obviously though, some people might prefer a ranged companion. For example, Lily could surely compete simply because she's fast as hell, has tons of health and with Oh Baby!, she also hits for truckloads of damage.
Well of course any companion with a 10 charisma (or high charisma) character would be badass, but it becomes a matter of preference.