I bring 3 x BLKNT and a light for IS CW.
I bring four EBJ for Clan.
Those are two very solid mechs imo.
As others have noted, best mech is a great circle jerk discussion starter but alot of it comes down to how a mech can be built, how that build intersects with a player's skillset and the intended role one is trying to fill.
Objectively, quite a few mechs carry the right blend of hitbox, quirks, firepower, mobility and speed in a game that tends to reward those areas the heaviest (vice the niche badasses like BNC, MAL, DDC or S). For me personally, its the EBJ, BLKNT, FS9, ACH, SCR, and to a lesser degree the TBR.
There are other great mechs out there but they feel more role dependant than the above so they slip from current consideration in discussing an overall best.
Edited by Lukoi Banacek, 01 March 2016 - 01:18 PM.