No Right Answer

So this one time I started dating two different guys at the same time. One I felt safe with and I felt had more potential for longevity. The other I had a lot of fun with and could talk with really easily but didn't necessarily see it as a "serious" possibility. I had a hard time choosing between the two, but ended up choosing the guy I felt safe with.
That relationship ended about a month later. I just never felt excitement with him and I wondered if I made the wrong choice.
I was still friends with the "fun" one and had seen a different side of him that made me wish I wouldn't have given up on him. We talked about it later I let him know how I felt, but at that point he was dating someone else. He told me it was strictly timing. It was hard wondering what could have been.
I recently found myself in the same situation. I was dating Mr. Safe and Mr. Fun.
Remembering how I felt the first time I decided to try with Mr. Fun. That lasted all of two weeks and I think about Mr. Safe all the time. Wondering if I blew that.
WHAT IS A GIRL TO DO? How do you know where to go? Have I been making wrong choices? How do I not wonder what could have been or if I did the right thing?
All four of these guys are great guys, really top shelf, I could be happy with any of them so it's not like I'm choosing someone bad for me, but why does it happen that way? How am I supposed to know which direction to go?
Gosh dating! So over it!