I totally agree shop around, do tons of research.
Go to dealers and "test" drive the machines. Set
a budget and do not let sales people talk you into
something more than you want to spend.
I have 2 machines now, my first machine had a 5x7
hoop as the largest and at first it was fine for me. But
after a couple years I started seeing designs that I really
wanted to get and make but couldn't because I didn't have
a larger hoop.
In January 2012 I purchased a new machine that has a 6x10
hoop and I am much happier (for now at least LOL).
Both of my machines are Brother's and they are fairly user
friendly and they are both combo machine meaning they do
both embroidery and sewing.
If you have a fantastic machine already that you like you may
even consider going for an embroidery only machine.
Just do your research and ask lots of question. Make a list of
features you want from the research you do.
Good luck and let us know what you get. We are here to help
you as much as we can.