Do u want to read manga online? This websites Completely free, No registration required, and best of all, no downloads! =)
There are over 950 manga series, and is always up-to-date.
Heres the Website.      www.onemanga.com

Click on the link, and on the top right corner, click on the Drop-menu which says”select manga series…”.

Obviously, select the series you want to read, and click the title. Its sorted alphabetically, just so you know. To make it easier to find, type the first letter of the Series name one your keyboard, and voila, it automatically goes to the letter.                                         

once youve selected your manga, click on the chapter you want to read, and then click “begin reading manga” One youve done that, to go to the next page either click the page, or use the right directional button on your keyboard. to go to the previous page, either click the button which says previous page, or click the left button on your keyboard.

So come on and get reading! =)

Hope i helped

This is the sites top 25.
Naruto (1) 
Bleach (2)  
One Piece (3) 
Fairy Tail (4)  
Full Metal Alchemist (5) 
Historys Strongest Disciple Kenichi (6) 
Hajime no Ippo (7) 
Katekyo Hitman Reborn! (8) 
Air Gear (9)  
Vampire Knight (10) 
Mahou Sensei Negima! (11)
Claymore (12)
Skip Beat (13) 
Detective Conan (14) 
Ane Doki (15)  
Soul Eater (16) 
D.Gray-Man (17) 
Shaman King (18) 
to-LOVE-ru (19) 
Eyeshield 21 (20) 
1/2 Prince (21) 
Tsubasa Reservoir Chronicles (22) 
Kekkaishi (23) 
Ouran High School Host Club (24)
Hunter X Hunter (25)