Pre-modern weaponry. Specifically crossbows, swords, daggers, pikes, battle axes… you get the picture.
I’d hire you to open my gallery. 
In a similar vein: I’d collect every passport stamp for the National Parks. I have a decent start already, but a million smackeroos would get me the rest of the way in style.
I would use the million to “collect” interest from a bank account or certificate of deposit. Then use that interest to supplement my income and collect stuff like memories, adventures, and anime!!
anything and everything home theater related
Pianos. Anyone know how much a Fazioli F308 costs nowadays?
I’ve seen a Vacheron Constantinewhich costs $150k, so you wouldn’t have that many in your collection. There many watches in the $20k to $25k range, so after you get the Vacheron you would only have 30 some-odd models if you stayed in that price range.
And, yes, I would collect watches.
Stratocasters.
I would collect musical instruments that I play; basses and tubas. Especially the odd special use ones like a sub contra bass tuba (down an octave from regular tuba), and a contrabass trombone.
I would put, say, $200k each into bettering five different collections. I already collect many things - mostly 1920s-40s oriented.
I hate it that people with really great stuff are always such specialists that they can’t enjoy anything else. It doesn’t say much for the objects and how dynamic and fun they are.
I would collect sycophants.
Horses! I would buy huge tracts of land with appropriate facilites (or build them if need be) and scour rescues and auctions for abused/neglected/mistreated horses - especially ones with unresolveable medical issues that relegate them to “pasture ornament” status and seniors who have put in many years of service to their humans who deserve a comfortable retirement.
I already collect jewelry, so I would have no trouble at all putting an extra million into my collection.
Yes, that is true. So I will go with antique MatchBox cars, the original Lesneys.
Fountain pens, both vintage and modern, but not the stupid flashy collector ones that are intended for collecting only, and have tiny pieces of famous objects built-in to them. I have a particular weakness for Parker, Namiki and SJ Dupont.
All-metal (wood grips don’t count), semi automatic pistols, with half the collection being devoted to Lugers, 1911s and Brownings.It would be cool to have one of each “high end” 1911s being made today: Les Baer, Ed Brown, Wilson Combat, etc. etc.
That sounded cool so I Googled it and right away I came up with two cars each worth $25,000.00 per car. And I didn’t even look much, so you can bet there’s probably a lot more expensive ones
Who’d have thunk huh?
omgomgomgomg…it’d be books.
It would take me months to narrow it down to a million dollars’ worth, though.
Edit to add: Books I want, not ones that are necessarily worth anything to anyone but myself.
I already collect game used hockey equipment so I’d use some of it for getting more. I also collect mouse and rat figurines and I’d really like to get my hands on the real Rizzo the Rat and Topo Gigio.
Interesting question.
I really can’t decide. I like football memorabilia, but it is hideously ugly (signed footballs and framed jerseys, for example.) I would also like movie memorabilia, but the space needed to display (for example) a movie poster collection would be extreme. I like sportscards and comics, but the rate at which they deteriorate is amazing. I bought cards less than 3 years old in an unopened box and they were melting. Even my old comics are starting to smell musty and are turning yellow. Collectible books have the same problem.
I guess I would pick something with low maintenance that would make for an interesting and beautiful display.