My opinion, based on what I have seen here, is that Gucci Envy For Men (about to be discontinued, if not already so) was relatively untouched in the reformulation that everybody noticed in the changed color. So buying any Envy for Men right now is smart.
Also Derby deserves honorable mention. At least as of the bee bottles.
Egoiste - I first smelled the vintage, and then the recent formulation. I felt that I could detect the change, but that it was actually a good change to my nose. The newer version seemed more in tune with modern tastes, yet the difference was very subtle.
Yatagan - similar story. I smelled vintage first, then bought the recent stuff. I was pleasantly surprised that the "oomph" was still there.