What weapons do you think are the best? I'd go with a .45, M-1 Carbine, M-1 Garand, Mosin Nagant, PPsh-41, Thompson, Springfield, B.A.R, MP44, and K98.
they are 2 different weapons designed for 2 different purposes, the bren being a very good LMG and the M2 being a very good HMG.
Just to point something out.... the Bren was (is?) a .30cal gun the M2 was (and is as I think its still in use) a .50cal gun M2 is heavier than the Bren.
The Bren was issued with a tripod but it's main purpose was until 1990 a squad automatic weapon. the Bren was in .303 cal untill the Nato standarisation which led to 7.62mm (.30) variants being introduced and used until 1990. The M2 could never be used as a LMG only as a HMG because of its weight, size and ammunition. It was designed for heavy fire support against dug-in positions, aircraft and lightly armoured vehicles unlike the Bren.
It may have been used to fill in for a HMG but that doesn't make it a purpose built HMG, the Bren was primarily as light support weapon with if needs be a sustained fire capability if needs be with a tripod bot in no way can it be compared with a M2 as a HMG because the Bren was not a HMG but a LMG.
Just because the Bren has (in desperate circumstances) been used in the HMG role (because they had no actual HMG) does not mean that it was designed for, or intended to fill the HMG role. I bet the guys in Dunkirk would have loved to get a load of M2s...