The first one is correct. "It is like" the best decision you can ever make.
Saying it that way, is the same as saying that it would be the best decision that you can ever make, but adding more to it. Almost as if soeaking to someone who is overdramatic, and constantly say the word like.
I hope this helps
Can you please put the sentences on so I can answer.
The answer is due and dew. Homophones are words that sound the same but are spelled and used differently. Inthis case, doe and act are not the same pronounciation as do.