First, there isn't a "best" 'mech or build in this game. Each 'mech and build are unique, and as someone stated above built for a specific purpose. Find the 'mech that matches your playstyle, and configure it's build to best exploit it.
And remember any new 'mech you take out for the first few times, expect to not be king of the damage and kill charts, it takes many, many matches to be good in any 'mech.
I primarily pilot a Commando or Raven and have died countless times learning how to maximize them to my playstyle (and each of those 'mechs is different). So now, after 1K+ matches in them, unless I catch a golden BB (or plain just **** up), I regularly do between 500 and 800+ damage, in rare games 900+. I only carry 2 tons of streak ammo in both of those 'mechs and rely heavily on my ML in the Commando and my pair of MPL in the Raven.
Please note; if you are accustomed to playing heavy and assault classes, you cannot play a light in that manner, you will get slaughtered each and every time. This is the biggest mistake I see made from people that claim lights are trash. In a light, your speed is your armor, once combat begins you should never, ever stop moving. And NEVER try to go toe-to-toe with another 'mech, you are not in an Atlas. In a light it's all stick (preferably in the back) and move; "float like a butterfly and sting like a bee".
Practice is everything, lights are probably the hardest 'mechs to learn to be good in because you have much more going on and everything takes place at a much more rapid pace. Plus, any errors made on your part are rewarded with instant death.
Edited by Spaceghost, 29 December 2012 - 06:14 PM.