I picked up one of these over the weekend due to broken central A/C and am very happy with it, especially since it was about $65 cheaper than the 8000 BTU LG at Home Depot. It's a little loud on high (all fan noise, not compressor hum/rattles) but you can sleep with it on low and it has plenty of cooling power. It has some interesting features like a dehumidify function and a "follow me" remote that monitors the temperature where you are and keeps the A/C running if it is still hot in a far part of the room.
It is very efficient and is only pulling ~550 watts. Instead of letting the condensation drip out, it lets it build up in a little well, then it flings it onto the condenser with the fan which improves the efficiency.
Costco doesn't sell it online but it is this model:
Looks like this:
They also had the 10 or 12k BTU unit for about $239 if you need a larger one.