For 95% of my long and short rides my standard carry is a PB Swiss tool. It has a "full" sized Allen key with an adaptor that the other tips plug into, plus usable tire levers. The tool is exceptional quality for what is essentially a real tool not a "multi-tool". I'm not dissing multi-tools, I have a few of them and like a couple. It's just that the PB Swiss is so good that it works like a full-sized tool. The PB Swiss hex bits don't round-out hex bolts like other lesser quality tools can. The only downside is they aren't cheap, but you get what you pay for.

An added benefit is that you can order separate bits from PB Swiss to tailor to your specific bike. The bits are around $3.00 bucks a pop though.