What are the best Kindle alternatives?

Kobo is known for being an .epub reader and with that comes a more open platform than Amazons offering due to the openness of .epub in general. eBooks can be purchased from a wide range of store due to the openness of the reader and do not even have to consist of only .epub files since it also supports a wide range of other formats such as .mobi, .cbz/.cbr, .html and .pdf.