Tide Ultra. Best stuff I've used. Occasionally peroxide will help with some stains, such as blood, pet urine, etc. But Tide Ultra is the best of the best so far, including compared with other versions of Tide and Gain. It's cleaned out Clif mocha gel stains from my white jersey, blood, muddy and oily grime from rainy rides, everything I've encountered.
The trick is to let it soak. Add a little concentrated liquid with a fingertip to the collar and stains. The enzymes need time to work. For tough stains I'll let the garment soak for up to an hour in tepid water. Thorough agitation by hand in a tub or utility sink can help -- machines don't always offer enough agitation, or agitate too vigorously and damage fabrics. Don't use hot water or warm air drying. Rinse under a full stream of cool water from the tap -- this can help dislodge stains after the detergent soak. Cool water wash and rinse and air dry. It's less likely to set the stain in case it doesn't come out the first wash.
I've heard claims that some complex detergents like Tide and Gain may compromise the wicking and elasticity of some tech fabrics. Some folks prefer detergents without dyes, perfumes, conditioners, etc., for their expensive tech fabric jerseys and shorts. None of my stuff costs that much so I handwash with Tide or Gain (comparable quality detergents). No problems that I can tell. But if you're concerned use Tide only for stubborn cleanups.