CD4, the Plymouth Bretheren and its offshoots (you know, the ones who gave us premillenial dispensationalism) are monst definitely not liturgical, yet they celebrate “the Lord’s Supper” on a weekly basis. My grandparents belong to this denomination.
Here in Australia there are two denominations calling themselves the “Church of Christ”. One is a respectable, evangelical group who go out of their way to be nice to Catholics, and the other is a distantly related group who consider themselves to be the only ones to have it right. I was invited along to one of their services in my Protestant days, and I had the hard word put on me. I was asked, “Describe the essence of Christianity in thirty seconds.” I tried to do so, and was told that I was wrong, and that they would spend an entire evening explaining it to me! I realised that there was some serious double standards at work. They also believe that “by their fruit ye shall know them”, and that good fruit is conversions to their denomination. Thus, enormous pressure is placed on people to convert friends. Every member of the congregation has a senior member who will supervise them, and make sure that they are living a holy life. It seemed to be very controlling and leaning towards being a cult.
I never went back.