Well, in the first place i've only played a few of the games. These including OoT, MM, WW, TP. Yes, i know, not very many at all. So naturally i will choose one of these.
Big Decision between Ocarina of Time and Twilight Princess. Let's start with TP.
This was pretty awesome to roam around. Why? Freaking ginormous. Humongo. Gigantirific. Every where you turned, there was a new piece of land.
The down-side? Barely anything, if anything to do at all with all of that land. Yeah sure, you can ride Epona (or whatever you name it) around, the bug search, and the occasional enemy along the way. What else? Nothing. Huge down-side when push comes to shove.
Next, OoT
There's just the mere fact that OoT is legendary beyond belief. Once you leave the Kokiri Forest, it's like "oh what's around this corner, oh that troublesome owl and- WHOA. SWEET." Bam, it practically hits you in the face, what with all the land spread out before you (and that wierd flying pineapple thing, or whatever it's real name is). To the left, lake Hylia, to the right, Zora's Domain and Kakariko Village. Smack dab in the middle is Lon Lon ranch, and beyond that is Gerudo Valley. ALL within basically perfect walking (okay, running and rolling) distance. Who doesn't love those skeletons coming up out of the ground as soon as the sun goes down? Ahhh... OoT.
Alright, so maybe I'm a little biased (just a smidge). And maybe there really is no competition after all. But you simply cannot count WW. Too much of the sea to enjoy galavanting around. MM was alright, but the game itself and the 3-day timeline was just too stressful to be able to enjoy actually roaming around and enjoying yourself.
With that, OoT it is. :yes: