Here is a little list of adjectives that you could use to answer the question: excellent, great, very well, good, OK, not bad (I don't like this answer because it assumes that you are expecting things to be bad), so-so, not good, not well, terrible, and many others. But if you want to have fun with your answer, you can reply by saying "PERFECT". People are usually very surprised when you answer this way because it doesn't happen very often. Usually, the other person will smile when you answer this way. Try this way with your friends and watch their reactions...

There are plenty of options. Not too bad. Doing alright. Cant really complain. I'm blessed. I'm doing good. I'm pretty good. I'm doing pretty good. I'm good.

if someone says:"How are you."You can answer him in many different ways. For example: 1. I am good. Thanks.What/How about you? 2.Not bad/good. Thanks.And you? 3.I am fine. Thanks. You? I hope that it is useful. It can help you.

The other answers have the details, but unless it's coming from a close friend, "How are you?" Isn't really used as a question. It's just a greeting and in most cases you just give a positive answer. I'd recommend, "I'm doing well. And you?"

Lots of ways. As another person wrote, the answers could be categorized as positive, neutral, or negative. I'll give you one example from each category: Positive: "Can't complain!" Neutral: "Getting by" Negative: "Could be better"