I haven't even bought my first handgun yet and I have a list a mile long of things I want in my collection. Good thing I'm still young with plenty of time to built up. The list looks something like this:
FNX-9
Mossberg 500 or Remington 870 Express
SW 686p
CZ 75 (75B)
Glock 17
Beretta 92F
Colt Gold Cup
FNP-45 Tactical
Desert Eagle Mark XIX .50 AE
Kahr P40
Walther P99
FN PS90
Colt AR-15
Colt M4 Carbine
Barret 82A1
Remington 700 CDL 270
FN Ballista
AK-47
Benelli M2 Tactical
FN FAL
M&P 40
Glock 35
Ruger Mark III
Sig P229
Ruger Vaquero
FN Five-seveN
Some are "movie/video game" popular guns that I will probably shoot few and far between (Barret and Desert Eagle) but they have always been "fun" guns that I am interested in owning. They are in no specific order after the S&W 686P. (FNX-9 will be my first purchase, then Mossberg/Remington, then 686p) After that it's really a crap shoot I'll buy as my interest shifts and turns. Not really into "classics", just want a variety of fun neat guns.
Honestly, I don't even know if some of those are legal to buy or not lol, just started looking up guns and typing them down as I saw them.
I don't think there are necessarily "must haves", but there are definitely widely popular selections like a good .22 (Ruger or Browning probably) and a 1911.