Have to agree that the Irvine Folk club is great. They've been running for something like forty years. I also should mention (in Scotland) the Girvan Folk Club, the Wee Folk Club in Edinburgh (it really is small but it's a great atmosphere) and the Stirling Folk Club. Another really fun one was the Dalmellington Folk Club. I had a warm welcome and a great time in all the Scottish folk clubs although some were better attended than others.