I can't believe that I haven't posted in this thread before, but here goes:
A part from the normal stuff, like: Balder, T-Express, Goliath (WW), Mega-Lites, pre-GCI Thundercoaster, SD2K, etc. that offers great airtime everywhere.
There are a few other spots that have a special place in my heart:
* Second twisty hill (technically third twisty hill on the layout) on the Mega-Lites are easily one of the best places to be, no only have they airtime, but the twist itself flings you out of your seat and increases the ejector feeling
* The tiny drop after the launch on Dodonpa gives the best floater I have experienced, the sheer speed and the tunnel really increases the floating sensation.
* I know that many people dislikes the Togo stand-ups, but one (at least) really gives the most sensational airtime I have experienced, the stand-up side on Milky Way at Mitsui Greenland have one big and a couple of small hills on it's layout and in the front car you can experience the most insane ejector airtime ever conceived, you are launched of the car
. Sure we all have experienced that feeling sitting down, but standing up is a completely different feeling, it feels like you are going to fall out of the car
(I'm not sure if the Togo stand-up "clones" produces the same thing after their looping, but I really hope so...).