My preference is large-scale, long-term RPG campaigns, generally rules-light, and typically focused more on character drama and feudal and interstellar politics.
Perhaps ironically, this means that my ideal BattleTech game doesn't really feature BattleMechs at all. They exist in the background sometimes, on those rare occasions the army shows up, but they are mostly ornamental - and when war happens, characters are talking regiments and jumpships, not individual mechs.
Think weddings and murders and betrayals and conspiracies and invasions, rather than robots shooting each other. This was always a big part of the BattleTech setting and plot, after all. If I read, say, the Clan Invasion storyline, half of it is battles and mechs and lasers, but the other half is a Davion prince falling in love with a Kurita heiress, or Victor deciding whether to try to deceive Thomas about Joshua, or Waterly trying to conclude a secret alliance with the Clans to take over the Inner Sphere, or Takashi swallowing his pride to hand over command to his son or to accept help from his old arch-enemy Hanse, or Sun-Tzu trying to get a read on and manipulate the other heirs at Outreach, or everything that went into the Second Star League on Whitting, and so on.
The "pew pew lasers" fans get all their stuff, and they can have games with little to no politics. At the same time, I get to have games with little or no mechs, but with a lot of soap opera drama. In space. With life or death consequences.
Which is what I'm all about. :)