Thats a pretty difficult question. At this point in time my top 10 best manga
1. Katekyo Hitman Reborn!
2. Super Lovers
3. Spiral The Bonds of Reasoning
4. Naruto
5. Hunter x Hunter (at least through Greed Island, since thats where Im at in anime)
6. Tsubasa Reservoir Chronicles
7. Tegami Bachi Letter Bee
8. Fairy Tail
9. Mousou Elektal
10. World Trigger/Shokugeki no Soma
HM: Haikyuu!!, Code:Breaker, One-Punch Man
World Trigger, seriously?
The manga has 2 chapters.