I highly recommend
T1, N1, and N5. T1 is the quintessential starter adventure, but it's not really geared for novice players, just for low-level PCs: novice players are likely to be slided and diced six ways from Sunday in that scenario, if
DM'd properly. Both
T1 and N5 (even if it is set in the Forgotten Realms
) are great modules for setting up a new campaign vs. being solitary dungeon crawls (like N1) . I also like L1, because like N5 it starts to bridge the gap between a dungeon/town setting via wilderness (though it's for a little bit higher level PCs than the others). B4 and B10 are also great modules than can easily turn into entire campaigns (along with X2, but it's not for starter PCs).
Rob Kuntz published a great low-level dungeon for the Castles & Crusades
d20 game called "Castle Zagyg: The Dark Chateau" which is quite good (though like L1, it's more for levels 2-3 or so and for more experienced players vs. novice players/level 1 PCs).
If you're looking to run a solo campaign (1 PC), and your SO decides to run a thief, the
d20 publisher Wyvern's Claw Designs has some great solo adventures for thieves that can readily be retro-converted back to
1e. They're in .pdf format and available @
http://www.rpgnow.com/default.php?manufacturers_id=279 I reviewed them for Polyhedron before it got merged into Dragon/Dungeon, and they're qiute good.
