Lets just say all round for one person isn't all round for another person. Last time I found 55-250mm all round for me... and only switched back to IS kit lens less than 2% of the time for wides. Now, my 85mm F1.8 earns about 80% of the time on my body and thats all round to me too. =) Sometimes learning how to setup your position to 'trap' (or catch -.-) your subjects is better than zooming.
Anyway, the closest all round with good quality might be a 24-105L.
Otherwise, Sigma 24-70mm is pretty decent, Canon's 24-70 F2.8L... pricey, but you haven't mentioned a budget... and then you can go get yourself a UWA for the less 'all round' situations.
Have you figured out what you're shooting most of the time?
Just for laughs... just buy any single lens out there..., they're almost ALL ROUND... perfectly circular in fact.