Sullivan's is a place that I really enjoy going to hang out. The setup of the restaurant is very open and informal. You seat yourself in a variety of tables or booths, and there is really nowhere in the place that you feel cramped. On the downside, it can be a little difficult to seat a large group together, but it can work.
There is a great selection of beer and a friendly staff. The food is pretty good but nothing stellar. I'm a fish and chips fan, and they do it well here (again, not outstanding but very solid). I did enjoy the Irish Egg Rolls, but that could have been because of the beer that was accompanying them.
It is the atmosphere that draws me to Sullivan's rather than the food. It is a laid back, easy place to spend an evening.