On my approach to KMDW today about 300 feet from touchdown after a 4 hour flight, ATC tells me to go around for another aircraft that's landing. Where was the aircraft in the air? NOWHERE TO BE FOUND!....
What do you do?!

Yeap, the same thing happens to me, mostly at busier airports which can be expected, but in FS9 you got the goaround if you came in line behind another aircraft and that aircraft just touched down, (or was rolling down the runway looking to taxi) which in my opinion was a bit more realistic. But the ATC in FSX is just
plane ridiculous (no pun intended)

. If I'm at decision height and the runways insight after I've been cleared to land I'm landing. I've been directed to land on water even thoe my aircraft isn't equiped with poontoons. And fegedabouit if you filed a IFR flightplan, you'll get sent 100nms out on a goaround and an ailtitude change 10,000' above the airfield elevation ( sucks when your burning up your reserves and your landing on fumes). Also what about the taxi and hold dance!
HOLY MOLY!, at a large airport you'll be an hour into your flight be for you even take off! Also the AI chatter just gets to monotonous after awhile (nothing like hearing a cessna doing touch and goes for an hour)

So anyways, these days I only use the ATC when I'm flying around my home base doing test flights. Other than that, like Strategic Retreat said, I mostly fly online. It's much more fun chatting with other simpilots that are out there on those long cross country flights. And once in a while you get some real intelligence up in the tower when someone wants to be ATC.