I am trying to get ready for ME 3, assuming I played to win, and not for completion. However I have never played the earlier two games before, nor do I have a strategy guide. How long would it reasonably take to complete them and be ready for ME 3.
Main Main Plus Completionist Mass Effect 17:11:56 30:44:28 48:26:54 Mass Effect 2 26:09:34 36:48:34 47:19:13
Main is the barebones main quests, no side missions etc, so is what you're asking for.
However, Main Plus includes additional side missions, etc, so if you just play "normally" instead of speeding through (and you should, a lot of ME1 and ME2 side mission results are carried forward to influence the later games so if your aim is to play the series it'd be a waste to skip these) then this is probably more representative of what you need.