#1
Does anyone know which sells the most units, Stratocaster or Telecaster? How would that number compare to the LP? I am just curious. I started out liking the Stratocaster the best but the longer I play with them the more I am playing the Telecaster.
#2
Stratocaster, by a wide margin. I forget where exactly but I have somewhere an interview with a couple of industry execs talking about the dominance of the strat, and one of the lines was something to the effect of "we don't release numbers to the public, but the strat outsells any other model from any company ten times over." I seem to remember it was ten, maybe it was five, and probably not meant to be taken literally anyway, but the point is that the strat is mind-bogglingly popular compared to any other electric shape out there and the undisputed bestseller. I don't know how the tele and LP stack up in sales exactly but the binary answer is "fewer."

It's not so surprising. The tele has always been very popular, and even more so lately with indie oriented looks being fashionable, but the strat has a titanic appeal across nearly every genre and market segment. It's the shape that people who don't know anything about guitars picture when they think of an electric guitar. 

This is just for body shapes/models among the major USA brands - the actual manufacturers make things very complicated. Samick for example almost certainly makes more guitars than any other company, since they run factories for dozens of giant guitar makers. There are a handful of companies that make enormous quantities of guitars for several different brands, often including their own. Samick might make nearly as many Strats as Fender does, since they do the manufacturing for Squier (or used to, I think they still do). There were a few years when they might have been making more Les Pauls than Gibson, back when they were making Epiphone guitars and Gibson didn't have so many cheaper models. It's hard to overstate how many more cheap guitars are sold compared to the expensive models. I'd bet there are almost a dozen Epi Standards sold for every Gibson LP Standard, for example. It's easy to forget on guitar forums that most consumers aren't going to sign up here to show us their brand new Squier standard strat, so it might feel like we see pretty even representation of Strat to Tele, maybe Fender to Gibson, etc., but the actual sales numbers are skewed super heavily towards strats, and cheaper models in general.