mangapark.com is a popular manga scans aggregator with more than 19000 manga sorted into around 30 categories. It has very clutter free interface with most recent scans posted on the front page. They have a free registration system where users can login and bookmark various manga and pages. Their site is also mobile friendly, so you can read the manga on your iphone!!. If you donate to cover their site costs you can actually remove ads on their website and enjoy ad free version. They have advanced search functionality where you can filter all the manga based on genre, author, no of chapters, rating and type. They also allow you to load the whole chapter in a single page which you can customize in the settings page and best of all no registration required for this!!