I'd second folks' suggestions of David Gemmell and Ben Aaronovitch, and add Christopher Brookmyre. If you've ever been into video games, Pandaemonium is a great read.
Jo Nesbo series about detective Harry Hole are really good - sort of books you don't want to put down. If you like the Dragon Tattoo series you will really like these - much better writing
... and for holiday reading in particular try Stuart Maconie, Pies and Prejudice is really good. He has a nice easy style
ditto the Nesbo and have you tried Arnaldur Indridason's books? 'Jar City', 'Hypothermia', 'Voices' and others. Great chilling (in more than one sense of the word) Icelandic based stories.
