One of my regular spots. It's open 24 hours on almost every day of the year. Generally friendly staff and good service. Big American-style portions. Pretty standard prices for a sit-down restaurant. Denny's is not just a breakfast restaurant, it's got a big menu with a lot of tasty items. You get your food pretty quickly.
The wait is gargantuan on a weekend breakfast or lunch hour, so get a reservation. It's better to go later in the day. There usually will not be any wait at other times of the day.
If you're ever craving breakfast or a good ol' American fatty dinner, Denny's should be a top option.