I just looked on flight radar for like, 15 minutes and this is what I found:
Beluga 
Privately owned L-39? Interesting
Cool Liveries:
Janet still at vegas:
And yes, they do have beechcraft
747:
Random drone, does anyone know what these normally are?
Mirage F-1 aggressor (one of these crashed at Vegas a little while back):
Military:
And apparently tethered balloons have reg. numbers
And that’s it for me. I doubt any of these are rare, but some of them are cool