Great Expections
Arms & Equipment Handbook: I *loved* the 2nd ed. version but it was stolen by some basturd who I never could find... this one I would hope would be a bit more crunchy and with pictures of EVERY weapon, but otherwise the same.
PHB 3.1: It's 3.1, not 3.5. 3.5 indicates fairly significant changes whereas 3.1 is an update, clarification, clean-up.
DMG 3.1: Ditto.
MM 3.1: Ditto.
Dragon: Five years ago I lost interest in Dragon. 3rd ed. came along and I picked up a few copies here and there but the price was too steep to warrant getting it regularly. However lately, every issue I've flipped through I've wanted... now if only the price would come down
Dungeon/Polyhedron: Dungeon was never my thing as I always ran games on the fly. I collected about a dozen of them mainly for the maps and traps. However, the quality is SO much better these days and a couple of the Poly mini-ads (especially the WWII one!) I'd love to pick up. There are other reasons as well, but let's not get into them... yet
Player's Guide to the World of Greyhawk: A 440 page, glossy, full-colour hardback with lots of art and maps and prestige classes and feats and a rogues gallery of all the cool NPC's and mini-adventures and a compilation of ALL material ever produced, even the conflicting stuff (just means people can choose) produced by the Canonfire crew

Sigh, if only it were true...