I'm embarking on some re-wiring and want to get good quality crimp connectors with soft plastic, not the nasty cheap Narva type. Can anyone recommend a good brand and supplier?

I like the wago 221 series connector. Being an ex electrical wholesaler I have heard good things from customers in the marine electrical field both commercial and recreational. They meets lloyds approval I believe. They are re enterable and do a range of cables from 0.4 to 4mm from memory. That means most circuits including data and instruments.

If you want a crimp connector then go for the double grip type from cabac

If you want male/spade/female/ring style, I like Wirefy connectors. They use a normal crimp tool, but are tinned and heatshrinked, which I like for marine installations.

Excellent expert info guys, many thanks.