I’ll second the Loch Ness Monster. I had to wait until my second trip to Busch Gardens to ride it, because my brother was too short and I didn’t want to ride without him. Great coaster — just enough thrills to excite you, but nothing too severe.
My favorite park for coasters is Cedar Point. My wife and I once spent two days there and still didn’t have time to ride everything.
My least favorite ride is Disaster Control (or whatever it’s called) at Cedar Point — just a lame State Fair-level roller coaster in an air conditioned building. Honorable mention goes to the Journey to Atlantis at Sea World San Antonio — there’s only one real hill in the whole thing, and you spend most of your time turning on the turntables.
Ah Cedar Point...America’s Roller Coast....Haven’t been there since 2000 but hope to catch up eventually on the new rides they have added. That said that year Millenium Force opened and it was the leading edge at the time.
Busch Gardens Williamsburg has a new one, the Griffon. 205 feet up, 90 degrees straight down. It just opened, and I haven’t had a chance to ride it yet. Here is the link to the website about it:
http://www.griffoncoaster.com/