G1-2-3 Against The Giants
What can I say but one of the best of the classic adventures. Haven't tried "Against The Giants, The Liberation Of Geoff" but it might be another way to get this series.
GDQ1-7 Queen Of The Spiders
Get them all at once! The D & Q adventures can be challenging for the players and the
DM though. Never had a party that went the whole way. They either chickened out or died trying.
T1-4 Temple Of Elemental Evil
I've run this one three times and it's always a favorite. Be prepared to spend a lot of time playing this, but it's worth it! If the players survive, and play smart, they will be a force to be reckoned with.
A1-4 Scourge Of The Slavelords
Excellent adventures and you get to beat up those nasty slavelords in the end, or maybe not...