Anything I can related to sewing/quilting. I have become a machine addict. I have 8, my daughter has one, so I can count 9. I have a few guitars, electric and acousitc, and a electric bass. I collect Enesco growing up girls for my DD, and quite a bit of dust these days. I have a collection of lighthouse figurines and SHOT GLASSES! Mostly the shot glasses are from places we visit...and magnets from those places!
We also collect antique vehicles, with our oldest being a 1955. I just sold my VW Beetle.
Other than my sewing-type stuff, I collect all the Nora Roberts and STEPHEN KING books I can! :D
And I keep all my quilting magazines.
I also am a Wilton cake pan collector. I had over 60 when I counted last. THUS, my SN, although I don't do much work with Buttercream these days. I prefer to work with fabric when I have the chance. It's so much easier to clean up!
Dodge/Mopar Matchbox or similar cars. Anything Mopar or Dodge! I have been collecting scale cars similar to the real cars I've had. (and trucks/SUVs).
There was a thread way back when called something like "what do you collect" that you may wish to search for. Very good! ;D