I love the AC/10 and I have ever since the very first Mechwarrior title I ever played. I know most folks think it's substandard but I want at least one if I can get it, and two are better. Because I have primarily carried at least one for awhile, I find that I can hit things at range and moving that I can't with uAC/5 or AC/5, or especially AC/20. The 20 has too much weight and heat for my taste and cycles slower than two AC/10. I've packed it on several different mechs and even tried them in the dark early days riding a Jagermech when I had no clue what I was doing. If it had a sound that didn't sound like a .22, it would be about perfect.
I like the uAC/5 and AC/5 next best when paired with SRM6. Fun load out for 55 tonners with mixed hard points

So, what's your favorite? I'm guessing it's some sort of laser for most of you all.