best mini tool for bicycle
Get the Topeak Mini Pro 18
What to Avoid:
Blades - Some people think it is nice to have a small blade. Why? The likelihood of using it is much lower than the likelihood that I try to take the multi-tool with me on an airline trip and get the whole thing confiscated. Do you still want a blade? Bring a small leatherman or a swiss army knife. Or bring a fixed blade knife or a folding knife.
"Have Everything" - What you need are allen keys, would be nice to have torx, potentially a chain breaker. You pretty much can leave the rest.
Tire levers - More of a word of caution. If you need tire levers to change your tires, bring two or three real tire levers. The thick and metal ones I have seen on tools will 1) not work 2) damage your rims or 3) both damage your rims and not work.
If you are okay with having a blade:
Topeak Mini PT 30
Topeak Mini PT20
If you want no blade and just allen keys, a torx, and chainbreaker:
Topeak Mini 18
You could have a set of actual tools. It will not be as compact. It will be more functional.
If you think you will not bring them, then get a multi-tool.
But you can fit everything you need and more in an saddle bag.
Small wrench tool
Chainbreaker - Park tools
Tire levers (full size, multiple)
Small multi-tool (swiss army knife or leatherman)
It will weigh marginally more
It will be more bulky
It will likely cost more, however, these are full-size tools that you can use with pleasure in your workshop.