I'm a fan of lingerie, so it's always hotter when the girl wears some than wearing nothing at all. I'm also a fan of clothed sex, not just for "something quick" in the practical sense, but because it feels a bit more for forbidden than regular nude sex. especially when the girl wears a skirt you hike up, pull her panties down, and stick it in, mmm.
However, if a girlfriend and I have the time and privacy, clothed sex feels redundant and it's better to express our love for each other in the nude (or lingerie and then nude).