Taking a long layover in Lisbon (May 21 - May 25, 2014) on my way home to the States. I decided to stop in Lisbon because it looks like I can enjoy the beach plus do a little sightseeing (I hope the weather is warm at that time of year). I am leaning towards staying near the beach and taking the train into Lisbon city center, but open to suggestions. It's just me, so I don't need anything fancy, just safe, clean and easy to get around using without a rental car. My budget is $85 or less a night if possible, but not set in stone. B&B, Guest House, Apartment or Hotel are all fine - just not a dorm style hostel - I prefer my own room and bath if possible, but that's not a deal breaker.
I am just replying to this one post, not your other, similar one. Lisbon is a great city to spend 4 nights and you won't run out of things to see just in that city. For starters, please see Rick's At a Glance list of sightseeing options for several cities at http://www.ricksteves.com/europe/portugal. You can get all the details, plus our hotel recommendations in Ricks' guidebooks, but note that the Portugal book currently for sale is a 2013 edition, while the Lisbon Snapshot book is only a 2010 edition (until new stock comes in), therefore we recommend the newer book. Most of the destinations on the Portugal list are easily accessible by train or bus.