Here are few suggestions to start off with.These are some of my fav top notch manga atm.I Focus on mainly seinen,Manhwa manga with a few Shonen exceptions.I will start of with more recent manga.
Sun Ken rock.(seinen )
Sun-ken Rock is a seinen series that blends comedy and a mature realistic side like no other series I've read. Just by reading a single volume you can tell this series has so much potential to be one of the best reads out there. The beautiful artwork really stands out as you read about Ken who is in love with Yumin but cannot reveal to her that he is the head of a local gang.
Tower of God.(Manhwa)
What do you desire? Fortune? Glory? Power? Revenge? Or something that surpasses all others? What ever you desire, 'that is here'. Tower of God.
Join Twenty-Fifth Baam as he climbs each level of the Tower to find his beloved friend, Lahel. Facing from impossible missions to mind bending puzzles as he uses any means necessary to reach the top.
Breaker and Breaker New waves.(Manhwa)
The Breaker is an absolutely entertaining manwha (Korean comic) that rivals and surpasses many Japanese manga series. If you appreciate great artwork, a strong story, and memorable characters, you definitely have to check this series out!
Theirs a good bit more.So feel free to add some suggest.I have read most of the good seinen,Manhwa and shonen manga.