I use the Mityvac MV7300. If you have shop air its the way to go. I've had the Top sider, gave it to a friend after I used the mityvac for the first time. Works for any fluid extraction. I use it to suck out stuck brake fluid from diff cyl, brake lines, coolant from reservoirs, etc.
In my experience, extracting engine oil is not always the best method. My wife's GLK takes over an hour of constant operation to extract most of the engine oil but not even close to all of it. So it can be very slow and inefficient for certain engines i found. I get more oil out via the drain plug on her car. I now put it on the lift and drain while I do the underbody inspection/maintenance. This is only beneficial if you have a lift though.
All my other cars/trucks get the extraction treatment.