i am a compleate noob when it comes to earth series and only have enough for 1 sadly so i was wondering which game will give me the most bang for my buck?
gameplay content and story and such thank you very much ^.^

I bought 2150 because it had the best reviews. Haven't played it yet, but I hope I made the right choice!

I found 2140 to be a rather awkward C&C clone; didn't get far but it did not seem very inspired at all.

2150 I loved. I've yet to see a RTS game which features a separate main base you build up the way you want and I have not seen that in my brief adventure with 2160. The pace isn't supersonic for the most part but I enjoyed the living crap out of the game. Tanks, skimmers, mechs, nukes and lasers, lightning guns and weather control, plasma, plasma everywhere. Cool stuff.

2160 was... prettier. Still, rather brutal at times, I found the unit design system extensions just that little bit annoying and the units seemed to be ridiculously squishy. I remember deciding to spam infantry because the vehicles popped as fast but I couldn't funnel enough in! I imagine storywise it's a bit more alluring as it has in-engine cutscenes and banter which was limited to large fields of text in 2150.

In the end, I barely played any except 2150. I like it far more than the other two though it does suffer weird controls and dated graphics.