In my opinion the best form of worship is to listen to harikatha.. Listen to discourses like Srimad Bhagavat, Mahabharat, Ramayan etc. It takes little money and effort as compared to a yagna or dyana respectively. All it takes is time and most of all it's enjoyable.We are transported to a different land as we listen to the awe inspiring episodes of the Lord and His many devotees. The stories are truly inspirational. They bring gnana, bhakti and vairagya in us. Listening to them rids us of our many sins and brings us punya. Since the stories also describe the wonders of the many Gods (there are 33 crore Gods and Goddesses) the listener gets the blessings of all of them. The content is not only history that happened several thousand years ago. The message it carries is relevant even in this day. There's wisdom in every word. It is said that listening to the importance of a holy place brings the same punya as actually visiting it. For example it's as important to listen to Venkatesha Mahatmya/Srinivasa Kalyana as it is to make a trip to Tirumala for the Lord's darshan. Knowledge or gnana is the key to moksha or salvation and true gnana is learnt at the feet of a Guru and not just by reading books.