Anouk and IlseDeLange have been the biggest names we have sent in 'recent' years. Trijntje Oosterhuis also had some hits in the 90s/early 00s, although her biggest hits have been mostly with others (Lionel Richie). Her song for the Johan Cruyff ArenA opening was a pretty popular song. Waylon had some moderate hits and was obviously known for his 2014 contribution.
Then, Douwe Bob/Jeangu Macrooy/S10 had some radio airplay on the national radio 2/3, but only a single top 40 hit song for Douwe and S10 (none for Jeangu) and they both were collaborations. They weren't exactly newcomers like Duncan/Dion/Mia, but they had little commercial success.
The years before Anouk, which really was the Dutch ESC Dark Age, had only two artists with serious commercial success apart from Edsilias return (really since 1998): De Toppers and 3Js. But well, they have commercial success in a niche that.. many would not qualify as very fruitful music. Before Anouk participated, 'serious' artists in The Netherlands had their doubts about participation in ESC. Nowadays, at least that doubt is lifted. However, I still don't see our commercially more attractive musicians contribute (in case of DJs) or sing (in case of the likes of Floor Jansen or Sharon den Adel).