Steve Lukather is most famous for being a member of Toto - a band scorned by many simply because everyone in it is a virtuoso musician. However, 'Luke' was also one of the busiest and highest profile LA session players of the 1980's. He appeared on albums by Michael Jackson, Cher, Richard Marx and Lionel Richie, to name just a few. Basically, if you heard a flashy guitar part on an '80s pop rock single, chances are Mr Lukather was responsible for it.
These days, he generally splits his time between Toto and his own just-for-fun band Los Lobotomys (check out the album Candyman for some blistering playing!).
For all his versatility I tend to think of Steve as a turbo-charged blues player: all the standard blues ideas are present - bends, vibrato and pentatonic scales - but they're played with a modern tone and some serious bursts of tricky alternate picking. In short, loads of fun!
One of the main facets of Lukather's lead style is the blending of pentatonics and modal scales which gives his lines a more sophisticated sound without trespassing into jazz territory (though he can do this as well...grrr!).
Soundwise, it's fair to say that Steve is not afraid of technology - he was one of the first to popularise the Ridiculously Huge Effects RackTM and for a long time was associated with Valley Arts guitars. These days he has a signature model MusicMan guitar, the 'Luke' plugged into Rivera Knucklehead amps. To replicate his tone, use a bridge humbucker- equipped guitar (with whammy for Jeff Beck impressions) and a full distortion with boosted lows and highs for a rich 'produced' sound.
Ewan Smith, Steve Lukather blues, Total Guitar, February 2000