Acoustic FIRST. At least for the first 1-3 years.
If you don't like the fretboard or the strings or how your fingers hurt or how difficult it is then that's a good time to stop.
If you can apprecite the acoustic guitar then that is a great step ahead towards more better stuff.
However, at issue is why people want to learn the guitar?/? Many have 'heroes' who, these days play strictly electric guitars. What a bloody shame. Many popular guitarists from the 60s-80s could all play the acoustic guitar.
Honestly dude, it depends on the type of music you want to play. Having said that, if you want to play with feel, then start with an acoustic.
If it's there, within you, then it's going to be a great start. And if it's not, at least you'll find out early. 8O
So, in conclusion, like any decent "A' level GE paper, if you truly want to be a good guitarist, you need to know how to play an acoustic - folk or flamenco or classical. It truly helps you to appreciate the instrument. And that my friend is all that matters whether you make it or not. 8)
Cheers
RoRK