You might try digikey.com and see what they have in
the way of transistors. Mail order and kind of speedy
in their delivery. Prices aren't too bad either.
I've also had good luck with these guys, but their
IC inventory is not as extensive as digikey. They seem
to be very prompt. Lots of tools and supplies.
I start with Newark, Allied or Digi-Key and go from there.
If I can't even wait one day, I'll try a local supplier or a nearby Radio Shack, but the Shack has almost zero inventory of hardly any parts, like a 741 op amp or a 555 timer, but not much else.
Digi-Key at digikey.com is probably your best option as far as availability and selection goes. If you want to get general parts such as capacitors, etc. on the cheap, it's worth checking out All Electronics Corp at