there are several single yarn cast on's,
simple (script letter e)
Twisted simple (it has an extra twist in base (better than simple)
Knit cast on
cable cast on.
its always good to know a few cast ons..
but i am obsessive and have taken it to the nth-(i know 35 or so cast on's!
here is a link to part 1 of a 5 part tutorial about cast ons, (part 5 is to cast off's)
each part has a link to the next.