Alex has given you some good suggestions, and I'd agree that 'Clearly' is a good word to use. 'Of course' is another phrase you could add to the list. I just wanted to mention a couple of things to be aware of. 'Surely' doesn't mean 'I am sure that'. It means (as Alex has pointed out) 'You must agree with me' - so be careful how you use that phrase. Also, be careful how you use the word 'Obviously' as it can offend the listener. In some cases, if someone says 'Obviously' in a certain tone of voice, it might suggest that the speaker thinks the other person is stupid/unobservant. So please be aware of that!

I wouldn't worry too much about using 'obviously' - it is very commonly used in English. You can also use 'clearly' as it means much the same thing. The other synonyms have more precise meanings. - evidently, ... -- there is evidence to support the statement - surely ... -- (as in, "you must agree") - without doubt, ... -- there is no doubt at all that ... - noticeably, -- a bit archaic, and not really used in conversation. - assuredly -- also a bit archaic and not really used much anymore. Hope that helps.