I've got the most speed with
Slackware. It's not ridiculously easy like the Ubuntus, SUSE, or Fedora, but it's not as hard as LFS. I can get it to boot up in less than a minute with minor tweaking after reading the
Slackbook. Even using the "slowest" of the included desktop enviroments (KDE), programs load faster than they did before Slack. It's regarded as one of the faster distros around simply because of how simple it is. And it let's you be a control freak so you can make it real complex or more simple... and faster... if you so wish.
Check it out. You'll learn a lot of linux that you'll remember even if you don't keep Slackware. It's among the most popular distros and the forum here at LQ is not only the official forum, but it's full of great information and very knowledgable people.
Good luck.