The one weaponless marital art I would like to become adept at is - spanking.
"No ray of sunshine is ever lost, but the green which it awakes into existence needs time to sprout, and it is not always granted to the sower to see the harvest. All work that is worth anything is done in faith." - Albert Schweitzer
IMO, Kali (a Filipino martial art) is the best. Although not a weaponless art, but you can always find an improvised weapon. This is particularly important, because, in an actual combat, you are likely to be outnumbered.
Hells yes. Eskrima/Kali FTW. I'd learn that. Or Krav Maga which was also missing from the poll for some reason.
Jeet Kune Do. I've done Tae Kwon Do and while it is a beautiful art it is not that practical in a street fight unless you are of a high level respectively. Jeet Kune Do is designed to be personalized to the individual, only down side is that it is taught by hardly anyone.
"Daito-Ryu" Aiki-judo-jujutsu - its the common link between Judo, Aikido, and Jujutsu. Its mainly comprised of getting your opponents into a defenseless position as quickly as possible with the least amount of effort. It involves alot with submissions, throws, grapples and such, but also one-hit-takeouts, which I think is genius. Because if you think about it, there are a lot of ways to take somebody out of a fight really quick. Knock the air of out somebody the right way and they're gasping for the next 30 seconds or so (AKA: SOL irl)
Because you can't spell "Slaughter" without "Laughter"