Season 6 - the Singed meta...a counter to Jax, Diana, and Irelia all in one...
Jokes aside... Singed is a great AP top lane counter for Jax, Garen, Riven, Irelia, Fiora, Nasus, Shen, Wukong. Only a handful of champions can really give Singed a problem, namely Warwick (the worst), Darius, Rumble, Kayle...mostly everyone else Singed can go even or beat by using different strategies at different stages of the game.
I've played over 350 ranked Singed games since S3 (my start) and maintain an overall record of 225-142 which is a little over 60%. This means Singed has been viable in all the different metas even after removing Force of Nature . It's the player that makes the game. I've won 4v5's and carried so many games with Singed, I often deal the most damage on the team as well as soak the most.
I've built and used different rune setups on him throughout all these games, but have found your typical mid lane AP setup with double doran start is the best way to win. If the top lane and jungler are both AD you can run full AP+armor page for an even greater chance to crush your lane.
My current favorite build:
Start: 
First back: 
First major buy: 
then 
Final build:
This item is situational: 
I only build 
if they have 3 champions or more with targetable hard CC.
With this build and your ultimate, you are tanky enough and cause so much damage to seriously disrupt every team fight that you have to become a priority target. This opens up the rest of your team to crush them...
The downside to Singed is that Singed can't do it alone. Teammates really need to rally around his game play style. Not being grouped with him, but being ready to clean up the messes he makes...people just love chasing Singed. Teams usually send 2-3 people to kill you, leaving the rest of the map open for your team. They just have to be coordinated or your efforts are for nothing and will be detrimental to the outcome of your match.
Feel free to watch some of my funny Singed plays: http://plays.tv/u/aFriendlyTroll
or ask me any questions about Singed strategies or match ups and I'd be happy to spread some knowledge. I still have fun playing Singed more than any other champion, it's the troll laugh.
