What size Mr. Tuffy Liner should I buy for my 24"x1.95" bike tires? Mr. Tuffy size chart is here: http://www.mrtuffy.com/sizes.html

My tire size is 24"x1.95".

If I go by tire diameter, I should go with Mr. Tuffy's Blue liner which fits 24"x1.375".
If I go by tire width, I should go with Mr. Tuffy's Brown liner which fits 26"x1.95".

Since the liners are supposed to be on the long side and should overlap, I'm leaning towards choosing the brown liner. 

For those of you who have experience with Mr. Tuffy's liners and its installation and use, what do you recommend and why?

Thank you.
I'd recommend none. They're more likely to cause flats when installed improperly and increase rolling resistance and weight. You're better off purchasing Kevlar belted tires/ puncture resistant tires, or if you live in an area with thorns, thorn proof tubes. You should also make sure your rim tape is properly installed and your tires are properly inflated - with this, and the right tire choice, they should be unnecessary. 

See also this question.

Also, 1 3/8" is not the same as 1.375 inches when sizing tires, necessarily (see Brown's law of tire sizing). 

While I do not use Mr. Tuffy liners, I'd think the 26"x1.95" one with a bit of trimming is the way to go in this case if you still choose to use one.