We did the one on I-Drive next to where Race Rock used to be.
It was quite interesting and went close to US and IoA, Seaworld, Aquatica and came back down the 4.
As I remember though it was quite expensive but for that we got loads of pics and was able to take plenty of video while we were up there.
The helicoptor itself is only a 3 seater and there was 4 of us - but that worked out to our advantage as they charged us all to go up once, then let the kids go up for free on the second trip (first trip with Mum second trip with me
)
I don't know what route any of the others take, or the prices, but I guess it would be worth checking that out first to make sure you get to see some interesting sites.
Some of our pics from the trip on in my trip report in my sig - Feb 2009