not too sure about bars in SS/malgrat for entertainment, but you can go into the hotels. try going along to where the resorts join as most hotels in that area have turns on that can be seen from the road.
in lloret you could try the robin hood at fenals(my local while i'm in spain) which has karaoke a couple of times a week, or the picadilly bar on lloret seafront which is popular with the ex-pats, or the irish rover which is just of the main street near the seafront.

Jimd-f is correct about SS/Malgrat in that most of the entertainment is outside the hotels. As you walk along the main road you will see crowds of people stopped on the street watching the acts (mainly bands doing covers or requests). If you like any of acts grab a seat (it will usually be patio table and chairs that have been put out for the night) and a drink from the bar. There is a road of bars that will do Karaoke, Quiz's etc in Malgrat - I can't remember the name of the road but a lot of the bars are in it (Robin Hood, Rovers Return, Champions Sports bar, Eureka Corner bar, legends etc). My personal preference was legends which had a quiz most nights and everyone won a price
If you're looking for a good Spanish bar, head for The Swan Scottish bar in Malgrat, it is by the shops and train station (from what I can remember this was the most expensive bar in Malgrat, but it did have a good beer garden out the back). 2 doors down from here you'll find a very good and cheap Spanish pub (opposite the train station). The prices were incredibly cheap in here and they also had a beer garden out the back as well.
I went to Lloret about 15 years ago and I'm not sure if most of the bars that I went to are still open, but I did go in the Robin Hood pub in Fanals and thought it was very good (maybe why it is still open). There were numerous Spanish bars in the side streets that did some good food and again were as cheap as chips