I freaking LOVE outlining. I know a lot of writers like to wing it, and there's nothing wrong with that, but don't knock outlining until you've tried it. That's all I'm saying.
Everything you love about winging it is what I love about outlining. It has the mystery, the discovery, the excitement of uncovering a new story, getting to know new characters. I love the random scenes that pop into my head like a movie trailer. I love sketching those scenes out, then figuring out the plot points that connect it to the other ones.
Outlines are fast. It takes me months to finish a first draft--usually over a year. But I can sketch out a world and an outline in less than a month.
Outlines give me faith the idea is sound. The plot may change during the draft, but at least I know it won't crap out halfway through. You can't paint yourself in a corner if you start with a plan (well, you can, but it's a lot harder).
My inner editor is not involved. See, he thinks all those dialog and scene snippets I'm writing will never make it into the final work. Also he's confused by roman numerals.
And despite popular opinion, outlining does not suck the fun out of the draft. Not for me, anyway. The scenes I'm excited about outlining are the ones I'm most excited to write in the draft. What slows me down are the parts I didn't plan for.
If writing by the seat of your pants works for you, then by all means keep doing it! But if you've never planned ahead before, give it a try. You might be pleasantly surprised. If it helps, you can think of it like a first draft, but with bulleted lists instead of paragraphs.
Whether you outline or not, what do YOU love about your process?