R.I.P. Totalbiscuit. People associate proxy Siege Tank with him.
Here is a proxy Siege Tank build used by HuT against Probe in the recent WCS Challenger.
It seems that there is a “resurgence” of mass Widow Mine drop in TvP recently. The build could be a good option for the standard 1-1-1 paradigm in the metagame.
There is a TvT opening which many use, but I don’t see people talk about it. This arguably the safest and most versatile expansion opening.