It's a bit simplistic to say Hackensack is a nice local show; outside of Chicago it's the biggest show in the United States.  The London Show is probably similar to the London Show in format and size.  What distinguishes Chicago from other shows is the room trading.  If you can, a collector should try to do it once in their life.  I would otherwise agree with the Baron.  As to which show you'll go to will probably be influenced by what you plan to do in Chicago or NY. There may be more things to do in NY than Chicago.
		
		
	 
I don't want to get into a show war, but yes, it's a bit simplistic to say Hackensack is a nice local show; it's the largest show on the East Coast. 
 You get collectors and dealers from the Northeast, the mid atlantic, the mid south and the Midwest, I'd hardly call that local.  A nice local show is our Woburn MA show or the Annandale show in VA, those are nice local shows, if you are a local, it's a fun day out.
At Hackensack, there are about 300 tables and every major dealer from the East coast and the Midwest attends. 
 It's by far the best single day show I attend, the promoter does a great job of using social media and print advertising to bring qualified buyers through the door; he's not a table salesman disguised as a show promoter.
 Chicago is the show of shows, the premier toy soldier show in the country, Don beforehand and Roger now did/do a great job of promoting and like Bill the Hackensack promoter, they relied/rely on social media and print advertising to spread the word, both Roger and Bill send professional flyers, brochures and banners to dealers so we can help them promote the show.
Chicago is split into two segments, the steady, relaxed room trading and then the Sunday selling event, which is hectic at times for sure, but not insanely crazy like Hackensack is, Hackensack is a 6 hour buttault of enthusiastic collectors, Chicago is crazy in the morning, then it slows down in the afternoon as numerous attendees travel great distances to attend and begin the process of heading home.
As a dealer who's attended shows for over 20 years, first with Bill Murphy from Excalibur Hobbies and then as Minutemen Toy Soldiers, I give both shows very high marks.
And speaking of high marks, I also have to give a shout out to the MFCA show down in PA; Brad, Dennis and their club members put on a great show, it combines toy soldiers with model figures and has something for everyone, they deserve praise for their show as well.....................and lastly, although I've never attended in person, I've heard nothing but good things about the San Antonio show run by Andy at K & C, so there you go................