I've played MechWarrior on the SNES, MechWarrior 2: 31st Century Combat, MechWarrior 2: Mercenaries, and MechWarrior 4: Vengeance, and while the classic MechWarrior 2 still brings back fond memories, MechWarrior 4 was clearly the best of these.
I'm personally loyal to Clan Wolf.
Regarding weapons, I prefer energy weapons paired with a pile of heat sinks. I like energy weapons because I hate having limited ammo like you get with missiles or bullet-type weapons. Speed is also important to me, for which reason I don't like PPCs because once I fire I can go make a sandwich and come back in time to fire again, and I hate being unable to attack.
Regarding mechs, I like big mechs with lots of weapons and armor, but speed is again somewhat important to me. I tend to favor mechs in the 70 to 100 ton range, often using something like the Mad Cat/Timber Wolf, but I like to equip jump jets, especially with super-heavy 100-ton mechs that take forever to get around.