I alternate between briefs and boxer briefs, but since I could only pick one, I chose boxer briefs as I do wear them slightly more if only because I have more pairs of them. Also according to my wife, while the briefs show off a better bulge, the boxer briefs actually complement the look of my midsection and legs better.
I have a few pairs of regular boxers, but I very rarely wear them as I don't much care for the bagginess and lack of support for the junk. They are also harder to fit comfortably under pants without riding up, especially tighter jeans. They are only used for days when I'll be bumming around the house but still have to wear pants.
I have a few pairs of x-rated novelty underwear or thongs but only put them on for the wife occasionally as they are not very comfortable for extended wear.
I always have to have on some underwear and have never been comfortable with freeballin. I just feel better with some support for the twigs and berries and would be worried about any unforseen event like a rip or pee stains, let alone if you have to remove only your pants for whatever reason, you are essential naked from the waist down.