This is an image many of us will probably be familiar with; the YouTube homepage (https://www.youtube.com/). A website that gets 900,000,000 unique views a month needs to be absolutely solid in all basic web design principals and YouTube is rock steady.
YouTube has used proximity here to indicate which videos go together. The white space indicated by the square at the bottom shows the white space that separates groups of videos. The close proximity of the videos at the top shows that they must be related in some way.
Their alignment choices are not challenging to the form in order to make the site easier to use. Have center aligned videos in neat rows makes them easy to browse and the left aligned menu stands out from the rest of the page.
The main source of repetition on YouTube is in the video statistics placed below each video. Having a consistent video option layout makes it easier for users to know where to see video titles and video views while also being easy on the eye for being consistent.
Color and Contrast
YouTube uses a mainly white color palette in order to make the thumbnails on their videos pop more. This makes it easier for the user to browse videos without it being straining on the eyes. They’ve used the same concept in the menu on the side to draw attention.
Overall YouTube has a strong design that emphasizes the basic principals in order to create an easy to browse webpage.