Oh my word. How many people are on this board? Because that is how many different answers you will get. You need to narrow it down a bit. How much do you want to spend? What features do you want?
Personally I have a Pfaff. I have had Pfaffs for the last 30 years and absolutely love my machines. It has IDT which is a built in walking foot. But my new one is huge. It has a 10 inch throat and all the bells and whistles. It is very difficult to take to classes and retreats because it is so big and heavy and I am thinking of getting one of those small portables for that.