Call Recorder for Skype is one of the utilities I use the most, at least once or twice a month. Call Recorder makes recording things like podcasts simple: I can record three or four people at once, each with their own 720p video streams, and then edit them however I'd like later. You can also record just the audio. There are tons of options for quality and frame rate so even with a slower Mac, you can get a good quality recording. Sound quality is as good as you can get from Skype (local audio always sounds better than the audio you're receiving, assuming you have a good mic, I presume because of Skype's compression). While $30 might be a bit much for someone who would only use this occasionally, for me it has payed for itself multiple times over.
I also have to give it to Ecamm for support. I purchased this all the way back in 2013, and have never had to pay for an update. Rarely have I had an issue that caused it not to work, or caused Skype to crash, and the Ecamm team is always quick with updates and fixes.
TL;DR: If you need to record Skype calls, and record them with excellent quality and options, you won't find a better or more flexible suite of software tools to do so than this.