Here's a list of paid relays. They aren't used by too many others, but you are most probably getting less spam from these relays. 
nostr:nevent1qqs9cpp8fj8x667rku62ejp34qs2n5m3l9vztvukgvne80gamc23p3cppemhxue69uhkummn9ekx7mp0qgsxhue7mwl7xjxp7pxekuy0650mvqzyskqj4k45nuwhptgtvmtuw9grqsqqqqqpaynasn