Excel is still my number one choice when it comes to graphing and charting, or just first-cut exploring, but I have notice that Google Sheets is also becoming more and more capable in its charting department.
Do you know Google Sheets have Pivot Table? Do you know that it has a motion chart that even Excel cannot match (yet)? Check this video out:
This is not to say Google Sheets is the champion already. For example, in the video above, you will see that its sparkline charts are drawn floating over cells, while Excel draws its sparkline charts within one of its cells, which I much prefer.