3x8 vs 5x5 for lean-ness

So I've started lifting more consistently than I used to, but I'm a bit curious about one thing. I want to achieve a slim, lean look (as opposed to a big, bulky look) but I also want to add strength. I'm wondering if 3x8 or 5x5 is better suited for that goal. There seems to be a lot of debate about this kind of thing, but it doesn't seem like many people have asked about whether 3x8 or 5x5 is better for lean-ness. In case it's relevant, I'm a 28-year-old guy, 5'6", about 150 lbs, and I think I'm around 18-ish% body fat.