After more than 20 years in the deer woods, the grunt tube is my go-to. I use it alone and during rattling sequences to make them as "real" sounding as possible.
My next favorite is a snort wheeze, but I only use this on mature bucks that behave aggressively. I've tried it as a last resort on big boys that won't come in, and usually it spooks them off.
One thing I wish I'd used more frequently over the years is a decoy, even the 2D versions. I killed a nice buck 2 years ago that came right into a 2D decoy from several hundred yards away. He never took his eyes off it and gave me a perfect 8 yard bow shot.