They don’t have any idea of what character they want their date to have.They don’t even have a criteria for choosing a date. Find that special someone who will make you feel like a queen and treat you like a queen.
There are any number of reasons that a guy could have considered a "loser" when you are dating him, so you need to pinpoint the common thread that you seem to keep falling for.
Once you have identified the pattern in the guys you usually fall for, you need to look at how you can stop the pattern.
Try to spot indications that you may have missed in your past relationships that should have alerted you how they were going to turn out.
Did you catch your boyfriend checking out the waitress on your second date?
Do you date "bad boys" who wind up cheating on you the first chance they get?