If you want the widest, thickest, most padded strap money can buy, the Gruv Gear Solostrap Neo is one of the best out there.
If you don’t need or want such formidable padding, a Comfort Strapp is bloody excellent. Way less wide than the Gruv Gear but depending on the shape/angle of your shoulders it may actually be more comfortable. Also, its design means there is no need for strap locks on your bass.
If you like the concept of the Comfort Strapp but want something more premium feeling, the Sandberg Flexstrap ticks that box. The body of the strap itself is very very similar to the Comfort Strapp but the leather ends and buckles are much higher quality. You do sacrifice the in-built straplocking feature though.
All of the above straps have a strong element of “soft neoprene” to their feel. If that’s not up your alley and you prefer the slightly more “solid” feel of leather, my two recommendations would be the Maruszczyk leather straps and the Dingwall Levy’s leather strap. Both incredibly well made but the main difference is that the underside of the Maruszczyk straps is grippier due to having a suede surface, whereas the Dingwall is smooth leather on both sides so is more likely to slide. Depending on your tastes you may prefer one over the other and as you said your current strap is slippy (which you don’t particularly like) I suspect you’ll lean towards the Maruszczyks. They come in 2 different widths so make sure you pay attention to that when ordering. Some very nice colours on offer too.