Final Fantasy VI
You'll recognize this as the overworld theme for the World of Ruin, which you listened to for many, many hours while you were flying about and/or level-grinding in Jurassic Park. Actually, the first World of Ruin theme--you might say the real World of Ruin theme--is the haunting riff you hear as soon as Celes steps off the remarkably durable raft on the mainland. That track is just pure despair. Emptiness. A world of nothing but tumbleweeds.
You get your first taste of Searching For Friends, of course, when Setzer leads you aboard the Falcon, and the music is very appropriate for the moment, and indeed for the rest of the game after that moment, for which it serves as the theme song. It's morose, but it's hopeful. It's serious, but if you listen closely it's just a tad optimistic. Just like most of your World of Ruin game, as you slowly re-accumulate your team and gain uber-god powers. (Kefka gained his godlike powers by messing with the Goddesses; you gain yours by beating up dinosaurs and stuff while he sits around and watches.)
I'm not a big fan of most overworld music because it gets old fast, but this one is a no-doubt classic.