It's not D&D, but from what I have heard, "Masks of Nyarlathotep" (a CoC adventure) does this better than any other published adventure.
Both "Masks" and "The Enemy Within", which predate the Adventure Path idea, still have problems with the junctions. Sometimes the players need to get a certain clue to proceed which can be troublsome to provide them with. "The Enemy Within" does, IMHO, a better job: the players acquire a river boat and can drive along the large rivers at their pleasure. Different scenarios are waiting on th ebanks of the Reik river, but the PCs don't have to swallow the bait at once. The time pressure known from other adventure paths isn't present at all.
One of the included scenarios is even so cool that the PCs adventure at one side, leave it, and at some point find another clue leading them back.
The strength of both campaigns, shough, lies in the rather disjunct scenarios which give the payers a lot of freedom.
Another interesting concept is realized in a different CoC campaign: "Beyond the Mountains of Madness". It casts the PCs as members of a polar expedition, which severly liits their freedom of choice.

Many players may balk at this idea, but, if they get into it, it works very well.