If you haven't yet tried ruler quilting, I'd suggest getting a ruler foot and a couple of simple rulers. Westalee makes a nice starter set that includes the ruler foot and a couple of useful rulers.
Janome and Bernina make ruler feet for their machines that have an easily adjustable thumb screw so you can raise and lower the foot without having to break out the screw driver.
I love my Sizzix Big Shot Pro die cutting machine- it can use any of the dies made by Accuquilt and others. I use it a lot for managing scraps.
Anti-glue needles for your machine are great if you're using either the sticky stabilizers or spray adhesives- really cuts down on thread shredding due to glue build up. I got my first batch from Organ a few years ago, but I think that Schmetz and Superior also make them now. If only someone would make some for long arm machines that would be wonderful.
Rob