I own 2 sergers ( 1 is a backup), I do alot of clothing sewing and quilting. I just purchased my new embroidery machine and it came with a "overcast" stitch for serging, course you would have to trim the seam but it would work as a back up to a serger.
I wouldn't trade my serger for anything, one of the last made of metal.

Definately a embroidery machine. And if I had lots of money it would be the BabyLock Ellismo

I would say a embroidery machine. I have a Singer with the foot that stitches and cuts like a serger.

Embroidery machine, my serger rarely has been used, but I guess it depends on what you're planning on making :)

Embroidery machine. You can use it to quilt as well as embroidery

I have been very lucky to have both, thanks to my DH. Mine are not top of the line, but they meet my needs.
My serger is a Singer DH bought at Walmart, 5 yrs ago and I have used the fire out of it. Only problem was figuring out how to thread it the 1st few times. Got the hang of it and love it.
It was three or four yrs ago, DH got me a Project Runway, he ordered online thru Walmart again. The only thing I wish was different was that I wouldn't him into just getting a machine with a bigger hoop. I am not complaining, they are both very useful machines and our DGD loves to embroidery, she's only 5 and thinks she is really doing it. LOL
My husband also bought me a Mid-arm for Valentines in 2011, bargain and a half. My LQS was buying a new FANCY machine because she was going to do it for the public. We were lucky enough to get and at a wonderful price.
My machines may not be the high dollar but I love them all.
I think buying a NOT so top of the line to start with also helps you decide what features you truly use or are just there. I also believe the more computerized and fancy has I higher chance of something messing up.
Go with what you feel is right and it will work out!... Good luck and God bless!
Sorry if I stepped on anyone's toes, but my machines are perfect for me! I know some only want top of the line and that is fine. I would rather save that money and spend it on other things and of course FABRIC.