To begin, we're not allowed to recommend specific products, so I can't say to you that we as an organization or I believe that xyz raised bed mix is the best on the market. What I can say is that you're correct in wanting to buy raised bed mix for your raised beds. Raised beds require good drainage like flowerpots do. Raised bed mix is generally a mix of topsoil and potting mix (potting mix has little to no soil, and is really just organic material like compost). When you see what looks like wood chips in your raised bed mix, that's the potting mix. You want that. Over time, the potting mix part of your raised bed mix will decompose, leaving you with too much topsoil. To re-fluff your raised bed mix you can add new raised bed mix or potting mix and work it into your existing mix with a soil fork.
      If you're buying bulk raised bed mix (loose product that's dumped at your property), you should ask the seller where the components came from. You don't want undercomposted material because it could contain weed seeds. If you're buying bagged product, you should read the ingredient list on the bag. There may be extra ingredients like fertilizer that you do or don't want.
      This is a Fact Sheet from CSU Extension about soil amendments. It gives a good overview of different materials that can be added to topsoil to make it more fertile. This information should help you choose a raised bed mix that meets your needs.

Choosing a Soil Amendment | Colorado State University Extension

Soil Amendments