Gulliver is an adventurous soul, possessed with an insatiable wanderlust that makes it impossible for him to settle down in any one place for too long. No sooner is he back in the bosom of his family than his feet start getting itchy, and he yearns to head out to sea once more. Gulliver's undoubtedly a good man, as he shows on any number of occasions, but if one had to venture a criticism, one would say he's a tad immature, a man whose boyish taste for adventure often gets him into trouble.

Nevertheless, Gulliver's basic decency means that he's someone we'd always want to have on our side in a conflict. Observe how he expertly sends the Blefuscans packing when they try to invade Lilliput. And yet this episode also illustrates the man's decency. He'll happily deter the Blefuscans from invading, but what he won't do, even at the Emperor's express insistence, is wade over to Blefuscu and wipe out their entire fleet. Gulliver is much too good a man to contemplate doing something so wantonly destructive.

Another of Gulliver's positive traits is his intellectual curiosity. He loves nothing more than finding out about all the many weird and wonderful customs of the various lands he visits. In learning about other cultures, he also learns a lot about himself, about his strengths, weaknesses, and limitations. Not only that, but as his encounter with the Houyhnhnms ably demonstrates, he also gains a unique insight into the manifest deficiencies of the human race.

Gulliver is kind of an every man's man.  He's not too rich and not too poor.  He's not a scrawny guy, but Gulliver also isn't a hulk of a man either.  He's well educated, but not super intelligent.  For example, he studied medicine at a university and served as an apprentice under a master surgeon, but Gulliver also never really engineered any of his escapes from danger.  Normally, a hero character that is caught in a tight spot figures out some miraculous way to escape.  That's just not the case with Gulliver.  He seems more content to just wait out his situations instead of engineering them to his favor. Perhaps that makes him patient.  

Gulliver is also a people watcher.  He'd have a blast in a busy airport.  I suppose that curiosity about people is what led him to go on his travels in the first place. 

"My hours of leisure I spent [...] in observing the manners and dispositions of the people"

His genuine interest in other people allow Gulliver to easily adapt to the different cultures that he comes across in his travels.  His propensity to pick up other languages also helps him to adapt quickly.