Most of the alternatives that come to my mind are those referring to muscular or musclebound, but not suggesting attractive, and there may be problems with differences between Australian, English and US meanings.
Masculine doesn't always mean "muscle bound", often it means "mature, adult and able to take care of his family". For those who prefer people who don't pump steroids, you're focusing on the wrong kind of words.
When I was younger, I was a typical tall skinny guy, but I looked like a surfer, had a nice tight ass, worked out (surfing or hiking through the forest) everyday, and was in great shape. The teachers in my daughters' schools (all the way through high school) would stop to admire me walking away to the great embarrassment of the kids. Not everyone likes "hunky".
For myself, I prefer the typical Bear (broad, a slight paunch and lots of body hair) over hunky anyway, as they're big and comfy, easy to hug and much more relaxed than people who only focus on their looks. Best of all, they don't know just how many people find them attractive, which in a weird way, makes them even more attractive. Unfortunately, Bears have never been popular among straights, which accounts for their underestimating their appeal.
My cousin always insisted she appreciates middle-aged men with a decent (but not obese) paunches (fat around the belly) for much the same reasons. She claims "they look like men, not boys pretending to be men".