2004 Raleigh Talus, 2001 Motobecane Vent Noir (Custom build for heavy riders)
I use generic slime liners (called "stop flats") and they work great.
far better than thorn-resistant tubes
they do affect the feel on lower pressure tires (not by much but I can tell)
they add weight (if that really matters to you)
in some very high pressure scenarios they themselves can cause pinch flats (such as using them on 140psi tires)
I only use them on my mtn bikes, and for both 65 and 90psi setups, they work fine. If you get an armored tire and put the liners in as well, you have something so heavily armored against flats that you would most likely have to have a sidewall or pinch flat , or done something very very bad like run right through broken glass to get a flat....and I run through borken glass and never had a flat....I just dont reccomend doing that kind of thing though.
I've used tuffy tire liners for years. No problems at all. They do however tend to become more flexible and seemingly thinner after a few months in the heat and rain. I'm sure that whatever name brand liner you get should work to keep you from most flats.