Other than my Navy service on USS Nautilus, and an overnight cruise on HMS Churchill, the other subs I've been on include:
USS Narwhal (Groton, CT)
USS Los Angeles (La Maddalena, Italy)
USS Norfolk (Norfolk, VA)
USS Baton Rouge (Charleston, SC)
USS Torsk (Baltimore, MD)
USS Pampanito (San Francisco, CA)
USS Batfish (Muskogee, OK)
USS Lionfish (Fall River, MA)
HMS Alliance (Gosport, UK)
Holland 1 (Gosport, UK)
I couldn't go onboard, but got a close-up look at the WW1 U-boat
U-1 in the Deutches Museum (that boat has her side cut away so you can see the innards)
oh, and I almost forgot:
Nemo's Nautilus (Orlando, FL)