Hmmm good Q.
I would start by maybe collecting a specialty, that you like.
Like Radars, or maybe one of each prefix, etc...
That way, it is not technically "endless", but it is still fun to find lots of stuff. Always watch your change for getting notes that maybe have a mismatch serial number or something neat like that. Those are the most exciting - when you find something that is face value but really cool.
Good luck and ask as many Qs as you wish - there are tons of knowledgeable and good people on this site.
