Which tool cabinet is the best for your garage? That's like asking, "What's the best motorcycle?" Both are very broad questions with similar answers: "That depends. What sort of work do you want to do in your garage?" for the first query, and "That depends. What sort of riding do you want to do?" Full touring dressers aren't optimal for motocross racing and likewise, if all you're going to do is basic maintenance on a Sportster, you probably don't need much more than a small box for a basic set of tools.
On the other hand, if you're jumping into customizing your bike and maybe even fabricating some of your own parts, you'll need a lot more than what comes in a Home Depot briefcase toolkit. That's where cabinets like the ones below come in handy.