Just a general observation to start with - buy the biggest machine you can afford. If you start out with the capacity of only a 6 inch hoop, you will always want to embroider something larger. Most of the embroidery machines will also do sewing, which means you can construct the blocks for a quilt, sew garments or drapes, or whatever you want.
I've got a Brother Innovis 4000D which I have upgraded to a 4500D. I have 4 hoops, endless built-in embroidery designs, endless fancy stitches, it's really pretty amazing. The draw to the Brother brand is their contract with Disney. I have an entire section of Disney embroideries - the Princesses, Micky, Minnie, Pooh, the list goes on. Most people who have this machine absolutely love it!
The new Brother Quattro is unbelievable. The best thing is the ability to zero in on a specific spot to place your embroidery. You really need to see this demonstrated, because hooping correctly is hard.
All that being said, I have been wishing that Brother would offer the same size super large hoop that Pfaff has......but there isn't enough throat space to accommodate that size hoop on the Brother. Also on the plus side for Pfaff is an excellent software that is available to edit embroidery designs or create your own embroidery designs......but I believe their software is compatable with almost any brand of machine.