Recommendation letter from a research supervisor who was not satisfied with my work Is it beneficial/harmful to get a letter from a research supervisor who was not satisfied with my work? (I wasn't interested in that topic, but I kept working in the lab for the money). 

Or forget about that and instead focus on people who were satisfied with my research experience only?
Talk with your advisor about this. Depending on your relationship with your advisor, you may still be able to get a decent letter. Use the following formula:


  Decent letter > No letter > Bad letter


If your advisor cannot write you a decent letter you will have to find someone else who is. Do note that not having a letter from your advisor will be a huge red flag; you will have to come to any interview with a ready explanation as to why your advisor did not feel comfortable recommending you.