I have both styles and each one has its uses. The regular length are quite often the only ones that will fit in an area due to space limitations, but the leverage on the long patterns is nice where they will fit.
Long pattern for sure, but the standard are nice for a second set. I have found that the standard will come in handy when you have limited access to swing a longer wrench. I have a set of each in SAE, so far I just have the standard in metric.
You should really have both. You should also have a third set of stubbies to cover most situations.
You might get by with stds if you're usually working in confined spaces and long patterns if you don't have a lot of confined spaces but need all the leverage you can get.