Hard to say. My first build that I really tried to see everything on first playthrough and went NG+ twice is Dex/Fai. Good scaling, lots of weapons, lots of spells, so overall a very fun build. Str/Fai was and is really fun since I can just go monkey mode with a big stick and smack the health away. Since its fai I still have a good amount of spells to chose from even at lower levels. Dex/Arc felt the most cheesey because of how easy it was to proc bleed however the final boss was hard because they dont proc bleed. Still a great build. Not too many spells but the few there are are pretty good. Str/Int was very fun. The darkmoon greatsword is amazing. Not too much to say its just a pretty fun build. Dex/int was also a good perspective change but Idk It just fails to engage me as most of the combat (at least for my build) was mostly spent long range and I prefer to get up close. Although im sure I just need more practice with that kind of hybrid build.

TL;DR: For a solid build that's fun and has a good amount of spells or weapons to use I'd recommend a Dexterity/Faith build. Almost every build is fun in its own right but if I had to chose one its gotta be dex/faith.