While it's not near the station, I loved Hotel Five. It's accessible by bus or a short Uber/cab ride, and I was able to walk from the hotel to Pike Place Market, the Space Needle, and the Westlake monorail station.
I stay at the Moore Hotel, a couple of blocks from Pike Place Market and a couple of blocks from the Westlake Center. It is a short cab ride to King Street Station. And it is less than $100/night.