If you're carrying it physically on your person daily, I have yet to see anything better than Leatherman's Skeletool. It's light (5.0 oz), has the core tools (a

If you're carrying it physically on your person daily, I have yet to see anything better than Leatherman's Skeletool. It's light (5.0 oz), has the core tools (a rather sharp knife with quick-access mechanism, pliers / wirecutter, and a bitdriver with a philips/flat bit built in) which covers the most common situations one is likely to encounter, both on a daily basis and in an emergency. There's also a bit set and and extension available as accessories. The lighter tools generally are missing one or more of the above and the larger tools are A) significantly heavier and B) contain tools that aren't that useful on a daily basis (e.g. file, saw) and aren't really all that good IMO when you do need them.