So many possibilities :).
You could create an Events channel and create a different program for each tradeshow. This will provide you the ability to track each event's success and costs seperately. You should track costs in Marketo so you can gain insight into CPL, Cost Aquired lead, cost per success, associate revenue, etc.
As a standard followup, I've imported each event list into nurtuing with a Raw lead status so reps can cherry pick leads in SF if they want. However, those leads aren't their reponsibility yet. Those leads should go into a nurturing track to get warmed with the goal of elevating them to sales ready leads in the future.
Carey, if you need some deeper help on setting this up, let me know.