Yeah, if you have $850-1100+ US to spend, by all means the 24-105 is a good choice for a "walk-around" lens.
Poor man's version is the EF 28-135 IS... which has been sold in kit with various cameras (though it really isn't a "kit lens") and can pretty easily be found used for $250 or less. Image quality is virtually the same at the focal lengths they share.... except that the 28-135 actually has less tendency to vignette at the wide end. Out at 135mm, beyond where the 24-105 can go, the 28-135 is a bit soft wide open (f5.6). Stop down to f8 ideally. Of course, the L-series lens is slightly wider and certainly is better built and sealed. Not that the build quality of the 28-135 is bad. It's Canon "mid-grade" gold stripe, similar to other lenses just below the L-series (but well above entry level build quality). The 28-135 often has a slight bit of lateral play in the front barrel, noticeable when it's extended during zooming... it doesn't seem to have any effect on image quality. Both lenses are known to develop "zoom creep", which can be a bit of a nuisance (though it normally doesn't effect anything)... it's more common in the 28-135, but there are DIY fixes posted online... or just put a rubber band around the lens. Both lenses are close focusing, have fast/accurate USM and offer helpful IS.