The HG/SS Safari Zone is the best in the series. Even if you hate the "wait 140 days" crap, it's not as if you have to do that, it just gives you more Pokemon if you do. Even without that, it has the most variety out of any SZ. Actually, it probably has the most variety even before you get the placeable items.
The only beef I had with it is that it doesn't have any real indication of what will trigger more Pokemon to appear. You pretty much have to use a guide to know what to do. --- If you think Majora's Mask was one of the best Zelda games and would like to see a 3D rerelease, go here: http://petitiononline.com/MajoraM