I was a little worried about this hotel as I had read some reviews and had filtered for "worst" ones. I can safely say that all of the bad reviews are well off the mark.
Tokyu Stay Shinjuku Eastside is easily one of the better hotels I've stayed at in Tokyo. Larger rooms and great amenities. If you're looking for rooms similar to what you'd find in the US, with kitchenette and washing machine to boot, this is your place. It's a bit a ways away from all the action of Kabukicho, but I preferred it this way. My stay was much quieter. I wish it were closer to Shinjuku station, but otherwise it was a great stay.