I used to ride to work with semi slick tyres (Maxxis Overdrives) on my hardtail and these were pretty good in term of weight, rolling resistance, puncture resistance and they held up well on wet and slippery pavement corners.

The problem I have is that I want to ride offroad also eg on the weekends and not have to change tyres all the time and I don't have the money to buy another lightweight wheelset with matching XT disc rotors and cassette so I can have one set with slicks and one with knobblies.