Lets not forget Ubisofts uPlay which was absolutely shambolic. Blizzard's / Activision launcher was alright though. It did the job but no where to the likes of Steam which is really feature rich.
> Blizzard's / Activision launcher was alright though.
I'd personally say it was better as a launcher. Launching Steam itself takes relatively long and when its just in the background its just there idling with ~400Mb of RAM (specifically its WebHelper), which aren't a problem with Battle.net since it idles at 170MB or you can just close it since it launches way faster.