Extra shelves. For almost every cabinet I ordered one extra shelf so that I can fit more in and so that I have a back-up shelf for the future.
Costco's Slide-a-Shelf pull-outs for the baking pantry and for under the sink. Why not just use IKEA's Rationell pull-out? Because I want real wood for these oft used and/or dampish locations.
TIP: If you use the Integral hinge dampers your hinges will use up 3 inches of your width (1.5 each side), so keep this in mind if you are ordering inserts for your cabinets.
From Lowe's I ordered Rev-a-Shelf's false front tip-out adaptor hinges and trays.
I will use these to turn the false panels of my cooktop base cabinet into wooden spoon trays.
I also ordered Rev-a-Shelf 's pegboard system for the plate drawers. I think it is much prettier and more durable looking than the IKEA offering.
And last, I ordered Rev-a-Shelf's Bread Drawer kit to keep all our yummy loaves fresh.
And because I used eBates, I got 2-5% back on all of this!