ITMA is probably THE place to be if you are interested in machinery and innovation around that area. It happens every 4 years (so next one is in 2020 I guess) and it's usually in Europe as far as I know. Probably out of the small business league but it is where all the new tech is showcased first.
http://www.itma.com/IWA in Nurenburg, Germany is probably one of the more popular European Mil/Leo trade shows. It's like an Euro Shot Show..
https://www.iwa.info/enFuture Forces (it was Future Soldier when I was there) in Praque is smaller than IWA but it's alright. Prague is also great for beer, hookers and getting in trouble with the mob...
http://www.natoexhibition.com/You can't be in this business and not mention OR. Happens twice a year, winter (Jan) and summer (Aug). It's in Salt Lake City in Utah.. Good luck getting a hotel room anywhere if you didn't book it like a year in advance. If you get a buyer pass then be prepared to get bombared with swag.
http://www.outdoorretailer.com/ISPO is probably the biggest outdoor gear Euro show. Munich (?) in Germany.
http://www.ispo.com/Techtextil also has an Euro show that I think is good, IFAI has a small one in Vancouver, BC which is mainly industrial fabric (that means marine etc.). I think it's in March but I can't remember.
I think some of the guys from DIY Tactical had a booth at SOFIC (that's where some asshole from Eagle Industries said that they were "tactical hackers" and shouldn't be allowed if I remember the story correctly). If I was a small and agile business I'd probably try to get a booth there.
http://www.sofic.org/
