Internext was a busy show in January this year. LOTS of people in attendance and no doubt it will be the same next January.
As baddog said, if you take advantage of the Speed Networking then you'll definitely meet new people, but if you tend to be shy and not communicative then you may not gain as much benefit. I think he meant to give you this link though
http://www.internext-expo.com 
Internext gives you the opportunity to connect with fellow affiliates, program owners, affiliate managers, hosts, designers etc. It's free for affiliates and the Hard Rock Hotel rate is pretty cheap ($79 USD per night from what I can see). Out of all the shows you could hit, Internext is likely to be your best and least expensive bet imo.
A good way to get a 'feel' for how the show went is to check out JFK's pics on FUBAR, here's a direct link to his Internext 2012 pics -
http://www.fubarwebmasters.com/events.php?id=262
Good luck with your sites and your decision!
