When I used to play League, I was a pretty decent Swain Toplane.
I remember I had a consistent 60%-70% WR with Swain. He's really fun to play in top lane as Swain has tons of punish and sustain if you take Grasp runes. Hitting his simple E, Passive, Q combo chunks the enemy while healing yourself (passive heals stack with grasp). He's not that great for all inn-ing as his cooldowns are very high if you don't build CDR, but he stacks very well with team as a tank.
Top lane's also just pretty peaceful cause there's not too much to worry about lol