I found a lightly modded SMP that tries to feel like normal Minecraft but with some extra stuff that actually matters.
It has Lifesteal so fights can change your hearts and it also uses the Origins mod so you can pick a race with its own abilities. There is also custom content like a Halberd weapon so combat has more choices without getting too complicated.
People here like PvP and meeting other players but it still sounds friendly for builders and chill players too.
There is a big spawn safety rule. No PvP within 128 blocks of spawn and no griefing at spawn. You also cannot combat log or run into spawn to dodge a fight. Shops are protected from griefing anywhere. The world border grows as more people join and every Saturday it opens up to full size for gathering resources.
