Establish a budget, determine what you need in a machine, shop around.
Me, I am old school; I don't sew anything but quilts so fancy stitches are not a requirement. You might like a self threading needle. Other than that...
I sew on a 1970s Bernina 830. The back up is a 1960s Elna Super. If and when the Bernina falls apart (I'll probably be long gone from this earth), I'll buy another.
I know this doesn't help much but just figure out what you need, buy the most solid machine you can find and run it into the ground.
tim in sanjose