I remember seeing pictures of woodies with the tunnels, I think at Bell's, where it was a snake or a monster or something, looked really 60s-ish. Just today, I was looking on rcdb.com and the Viper at SFAW looks like it has a nice tunnel, up in the air and covering a drop(?).
The tunnel on Apollo's Chariot is cheesy, pop-up or drainpipe tunnels are good, like on Magnum, but that tent business is not cool, IMO. I really enjoy the tunnel on MF where you get your mugshot snapped, nice flash effect. Tents are just no fun, period. Fog, mist, darkness, it's all good stuff.
Wood is the best for tunnels, though. The Grizzly tunnel is awesome, and loud, and puts you somewhere else when you fly out of it. Lots of woodies should have tunnels. I've thought about going to Family Kingdom during the off season and building myself a tunnel on the Swamp Fox(j/k).......