A few novice questions


I've a decent enough knowledge of electronics but I'm not very big up
on what's being used today in embedded systems.

For instance, in my college course, we use chips in the "74HCT" family
and we use transistors such as BC337 and TIP121 as switches.

I've been asking around and it seems that developers nowadays are
using different chips and transistors to the ones I know about. I know
about MOS transistors, but I've never used one.

When working with the PIC16F684 microcontroller, I'd like to ask:

1) What kinds of chips I should use with it, e.g. 74HCT family, or
4000 family, etc. ?

2) What transistors should I use a switches when I want to pass as
much as an ampere of current?

Also, very quickly without getting into too deep a discussion, I'd
like to ask what microcontrollers I should be using? We've used the
PIC16F684 so far in my college course, but we also learned about the
8051 last year. What's the most popular microcontroller used for
simple things like lighting LED's and taking push button input?
.