I just got the ones I ordered from amazon -- Paper Mate "Mates" 1.3 mm mechanical pencils, a pack of 8 with brightly colored barrels, $5, ships free as an add-on item.
I didn't realize when I ordered them (although it's in the description) that the slightly plump barrels are also triangular... very comfortable to hold and less likely to roll off the table.
I haven't done much with them yet but really do love the way they write. Can't comment on durability, but they feel solid, and all of their mechanisms worked fine out of the box.
I'm really pleased to have a mechanical pencil I actually like!!
