If this is your first GenCon, DON'T schedule yourself for ANY events!
Even if you want to max out your Exhibit Hall time, the Hall is open from 10-6; that leaves several hours outside of that interval to fill. In fact, you may want to schedule an event or two in the middle of the day, just to get away from the crowds & insanity of the Hall.
Yes, you can find plenty to do with generics, but all the good/popular events will have sold out, and there will often be people waiting for space to open up. Search that event catalog, find games & other stuff you might be interested in, and sign up for them. There is True Dungeon, Escape Rooms, thousands of RPGs and board games, movies, seminars. To simply discount all events because of will-call issues is silly. You have 4 days, pack it with fun, and you'll sleep when you (or your characters at least) are dead. :-)
I concur with Buffythecatslayer, schedule yourself some events. Particularly the ones you want the most and try to get those when events go live. You don't always get in the game with generics.
We always schedule our arrival on Wednesday and use will call. We spent about 30 minutes in line waiting last year for Will Call and after having two people forget badges over the years the group consensus is will call is the way to go with a Wednesday arrival.
We have also discovered that taking the following Monday off and leaving Monday has been a good idea on our part. A lot less traffic and you can enjoy The last day of the con fully and since parking is no longer an issue Sunday evenings you can drive to any place to eat that outside downtown that strikes your interest.
I did...so call away, but I can show you my purchases from every year. I did say that I had an hour in between events and that some of them ended early, so...
hendelbolaf is an experienced GCer; for a first-timer, that full a schedule might be a bit of overkill. Give yourself time to wander around the hall, you might find some stuff that surprises you. Also, do take some time to relax; don't burn yourself out and then get home exhausted.
One thing I recommend is that there is a site (I'll post it when it's up with this year's list), that has a list of every exhibitor in the hall, with a link to the company's site or FB page. You can check out what they have going in advance, so it's a good way to do some targeted browsing & game demos. Someone also created a nice printable map of the hall, so I took that list, then highlighted the booths I wanted to hit.
Listen to Buffythecatslayer, I do NOT recommend a full schedule the first time around. One of my friends went for the first time last year and he chose a mix style of about half his time scheduled and the rest open with generics in hand and shopping/browsing. He enjoyed it. I think we all sort of evolve our own style for how to spend the convention. I agree that I go a little too gung-ho at times...just ask my son who goes with me! :)
I'll give another vote to the "don't overload yourself" tally - 4-8 hours of scheduled events TH-SA, wide-open SU, and 4-8 Generic Tickets can be a very fun but not overly taxing first time. There are so many events and things to see every year that you can't possibly do it all - but its nice the first few times you go to see what there is to *see* and then do some of it.
The dealer hall is an easy 8-10 hour visit if you take your time and *don't* do much in the way of demos. If you want to take your time *and* do demos, you can spend your whole con in there.
...and then there is everything going on in the after hours, at the hotels, at the bars, etc.
So much to do; so many games to play - even if you don't schedule a lot.
Some excellent folks earlier in the thread already mentioned Nascrag, so I'll mention the Plaid Chameleon 7th Sea LARPs. Hilarious, complex, and challenging.
My favorite event of all the Gen Cons I've been to was in 2010 I think. It was a home brewed d20 Modern game called Escape from Black Mesa. Fantastic GM, great players, fun pre-gens and fun story. It is still the highlight of all my years in Indy. I hope every year to find a game that equals it, but so far nothing has come close.
I always love seeing old and new faces at the Legendary DrunkAssParty (gonna be IX this year).
My favorite events thus far have been megagames. Creativity of LARPs/RPGs, mechanics of board games, narratives created by the actions of dozens of players in a large-scale social simulation where, just as in the real world, there's too much occurring to have perfect information.
The first year I played in one, I was part of the African Union team in a game of Watch the Skies (like a model UN but expanded to include military roles, science roles, spies, etc. - oh, and you have to react to the first ever sighting of aliens and figure out what their motives are too). Let it be known that the African Union succeeded in raising their prominence on the world stage, and partnered with the UK to rebuild mainland Europe after the great [redacted].
Second year included creating hope out of a bleak, zombie apocalypse Chicago by building a modern day U-Boat ark (thanks Museum of Science and Industry!). This game was My Kind of Town. I also volunteered as control (game master) for the NPC clans for a feudal Japan era game called Sengoku. If you want to read about that one, here is my After Action Report.
I enjoyed these so much that I now volunteer year-round with the Megagame Coalition. You can find their lineup for Gen Con 2019 at their website here. All of the games sold out last year, so they've expanded to 11 different megagames this year. Hope to see some new folks there!