Best digital cable to go for?

Hey guys, what is the best digital cable to go for?
Theta T to DAC. Rca / Optical / BNC are my options.

If so which format and brand and model please

I would go BNC. I will have to check out my cable at home as it is not a "name-brand" cable but a custom made cable using super-high bandwidth wire from a company in Colorado.
I would recommend to try Stereovox HDXV. $100.
It does have BNC plug covered by RCA "cap". It made a tremendous difference in my system when changed from $300 coax cable (I mean, positive difference). Superb value.
Kimber D60 or AGDL.
I have heard good things about the Stereovox cables.I sell the Omega Mikros.They have just launched their Zephyr digital IC at $375.It is available for a 30 day evaluation,should you be interested.
BEL D-1 via the BNC works best.
The Stereovox HDVX digital cable is amazing performance at any price let alone the $100 retail! Also connector on cable is BNC with RCA adaptor so you have your choice and no future obslolesence. HDVX is lightweight and very flexible so no installation hassles.

2-3 years ago I was happy with AZ Mc2 digital after comparison with many well reviewed contenders, then 1-2 years ago glass toslinks became widely available at prices under $100 that slightly surpassed AZ Mc2, now new Audiovox HDVX has beat out glass toslinks by slight margin and currently my reference.

Got to love it when cables get better and cheaper at the same mine at Cable Co.

AZ Mc2 -> Glass Toslinks -> Audiovox HDVX