i know, you dont start with it. when HL2DM first came out, there was what was known as the "gravgun noob". the gravgun noob would refuse to use any kind of real weapon, and would insist on throwing toilets at people rather than shooting them. now we have what is known as the "stunstick noob". the stunstick noob will stay in an enclosed part of the map with the stunstick, and use its amazing range to wallop people out of existence.
seriously, the stunstick has way too much range. ive been killed by it, even though i've been standing 16 units away from the stick.
but the S.L.A.Ms just pain rock. i'm surprised they didnt have a weapon like them in hl2. it was always great fun in hl1, when you placed a tripmine at one part of a level, then stood really far away, waited for a grunt to run near it then jumped up into the laser.