It is fun to blow up a titan in the middle of nme titans. Occaisionally (not often) I blow one of mine up to do it. (use ngm's at long range, or have it step into burning forest) I don't do it often cuz it runs through jocks and money.
I did make about 3 or 4 titans all named nuke. one in recon, heavy and assault, maybe light. They're there for the stupid AI to pick. Basically I slapped the biggest engine possible on it and thats it. Makes a large explosion. The only problem is that if you see one of these coming toward you, best to blow it up quick, before its in among your titans.
When I have long-ranged cannon/energy titans, I do aim for the chest as soon as possible, assuming they're far enough away from my titans. Center torso is more heavily armored than the head, but it's easier to hit. So as long as they are AWAY from my titans, I blow em up when I can. :)
Side Note, Newbies, do NOT do this!: The first titan I made was named Lumberjack, so named because it used axes. (lame, i know) When nearly done, I didnt have enough weight to do what I wanted, so I didnt put armor on the lower torso. I also didnt have enough space in the center torso, so I put the engine on the lower torso. I meant to use this titan, took it out into battle, and promptly got my jock killed in the engine explosion and slapped myself on the head. (I rationalized engine in un-armored part, because "lower torso isn't hit very often" yeah right...) It's kinda what gave me the idea for NUKE.