Midrange
Kawasaki Grand Hotel
A bit old, but with friendly staff, most of whom speak some English. Rooms are a little more spacious than most other business hotels in Kawasaki at the price, and have wired high-speed internet access. There's a 7-11 type place on one corner and an Indian restaurant on the other; they also sell stuff in the lobby. A hearty breakfast both Japanese and Western with endless coffee from their espresso/coffee machine is included with free Japanese and English newspapers. Plenty of clubs and other such stuff within 2 minutes walk as well, if you have the time and the money.
Hotel Mets Kawasaki
You will be hard-pressed to find a hotel that is closer to a station on the Tokaido Line between Tokyo and Yokohama stations. Free broadband internet and breakfast both Western and Japanese style available. Japan Rail Pass and JR East Pass holders receive a discount.
There is no compelling reason to stay here overnight and most visitors daytrip from Tokyo, but if you are splitting time between Tokyo and Yokohama and your destinations are on the JR Tokaido Line or the Keihin Kyuko Line and the hotels in Shinagawa are all sold out, Kawasaki might be a good alternative as there are many inexpensive business hotels in the Kawasaki area. Outside of the CBD there's a large highwayside cluster of motels in Shin-Maruko, near the Tama River.
Original Kawasaki Eki-mae
The popular no-frills Toyoko Inn chain maintains three locations within walking distance of the Kawasaki train stations. Toyoko Inn Club members can check in from 15:00.
Kawasaki Nikko Hotel
Part of the prestigious Nikko chain of hotels. This means, be prepared to pay.