For the past couple of years, we're thrown in some 1st edition AD&D here and there. We played two adventures so far:
S2 White Plume Mountain
C2 Ghost Tower of Inverness
A year back, after C2, I mentioned that the A-series was in the lead.
I think it still is in the lead. G1-3 (in this case, just G1 this year) would be fun but the pre-gens are a bit overpowered for G1 in my experience. So I'd either need to accept that, or allow the players to roll up their own higher-level guys.
G1 also has the issue of being extremely high-combat. This is a disadvantage for my GURPS players because it's hard to adjust to AD&D with combat - in GURPS, a well-executed combat can have no consequences for you besides some consumables expenditure and fatigue. That's almost never the case in AD&D, where every fight wears you down and a bad one can end your ability to progress in an adventure. So I'm not sure that's as fun as it could be, not just yet anyway.
The A-series is a bit of a mix of combat, puzzle-solving, and careful play. I think that's a good match for my players.
I'm not sure if this will happen soon, although I could literally pull A2 off the wall right now and run it tonight if I had to. But I'd like to get the ball rolling so we don't miss out on 2019's AD&D!