My wife and I used to go to these thing alot - not so much in the last couple of years though. We’ve gotten several 3 days trips to San Fransisco, Orlando, Vancouver BC and a couple other places. We’ve also gotten our share of cheap swag like “luggage” (read cheap nylon duffel bags in various sizes) a digital camera (kind of worked as a cheap webcam and later sold on ebay for $10 USD) a few B/W TV’s (make great gifts) and various other crap.
If you plan on going to just get the gifts I have the one line they have no answer to. When they ask how you normally take vacations tell them you go camping (it doesn’t matter if you do or not). Then tell them you have three large St. Bernards that go with you EVERYWHERE (it doesn’t matter if they don’t happen to be with you at the time).
All timeshares I’ve been to do not allow large dogs unless they are working dogs. Some allow small dogs with an extra deposit which is why you tell them you have three LARGE dogs. 
They will sometimes try the “what if you want to just get away from it all and leave the dogs at home” angle. Just look at them sideways and say “KENNEL OUR BABIES???”
After I started using the dog excuse, I was walking out with my free gifts in no time.
Almost all the timeshares I’ve been to will tag team you. If the sales person fails they call the “manager” over to drill you harder. Sometimes these guys are right bastards. But I’ve come up with a way to handle these guys as well.
At the start of the sales pitch they almost always ask if you’ve been to a presentation like this before. I say “yes and it was the single worse thing I had to deal with. They hard sold me on a product I wasn’t interested in and wouldn’t take no for an answer. Then the sales guy had THE NERVE to tag team sales pitch me. He said he needed to get a manager to ‘sign off’ on my prize but that was a code word for ‘send another sales person to repeat the pitch to me again’. At that time I swore I would never buy anything from a company that tag team sales like that. I hated it. You guys don’t do that do you?”
Of course they always say no.
Then, when they send the manager over repeat the story to them. The minute he starts the sales pitch you can simply say “I just told you I would never buy from a company that tag teams sales on me. I’m sorry, I just can’t buy anything from a company that says they won’t do something and then do it. That is a horrible way to start a relationship. I think I need my prize/gift and we should part ways”
There isn’t much they can say at that point.
The few times I’ve been honest up front and told them I was not interested in the product and was only here to collect the prize/gift were the worse hard sell sessions. I ended up resorting to just telling them lies to get my stuff.
Always figure these sales sessions will start late and run a little long. Most places have 20-30 people show up at once. They play everyone a 15-20 minute movie on what a groovy product they have. Then everyone breaks into groups for the hard sale. The sales person will talk about how much money you will save, how the company has seen tons of growth, how you are not buying a timeshare but buying a deed to property you own, and then break down how easy it is to afford. Then they tag team you to the manager, he goes through the entire thing again. At the end the manager signs the papers to claim your prize/gift. You go to the “claim office” and a rude person (Its always a rude person for some reason. I think it must be where sales people end up if they don’t make quota as punishment) will hand over your stuff.
Sometimes these can be kind of fun. A couple hours of time for some plane tickets and a few nights in an average hotel. Never bother for just a gift (hold out for vacations) and ALWAYS have them mail you what you will receive in writing before you attend.