I’d have to say the .357 Magnum, especially in HL2 where you can use it with the suit zoom like a sniper weapon.
I find Episode 3’s weaponry to be much more efficient.
My favourites have to be the pulse rifle (Nothing like beating the Combine with their own weapon!), the RPG/rocket launcher, the gravity gun (Especially the super powered one, which is lots of fun!) and the portal gun.
My favourite weapon is Crowbar, Glock Pistol, .357 Magnum, Spas 12 Shotgun, MP-5, frag grenade, satchel charges, trip mines, rpg, crossbow, gauss gun, gluon gun, hive-hand, snark, mp-7, gravity-gun, pulse rifle, HE grenade, pheropod, Tau cannon, Pulse cannon and the super gravity gun (blue).
crowbar…