I've stayed at the Century Hyatt before. As others have said, it's just a Hyatt, nothing all that special. Shinjuku seemed to be a decent place to stay for the first time in Tokyo though. Haven't stayed at the Hilton yet (check back in 3 weeks).

I would reccomend looking around for prices though (always check the hotel's website). Unfortunately priceline.com.hk had specials that end in March (not that they were any good) and Hilton/Visa extra nights thing ends in the middle of February. I do think that $220ish is a little more than I'd pay for that Hyatt and the Hilton.