Install all the games!
Hah. That's a bad idea at the moment. I can't really multitask while playing. It also does not help that I'm one of those freaks who can spend even five hours on a single X-COM battle 'to play the perfect game' ;). I know myself well enough to know that I can either graduate with flying colours while heavily restricting my play time or barely get by on C's and D's while playing all the time I want. Until summer I'm allowing myself one hour per day and even that will probably need to go around exams.
If you're not talking about old school X-COM, I'll be so disappointed in you.
I think the new ones dropped the dash. Out of curiosity, what didn't you like about the new ones?
Single base. Limited squad size. Fixed results for actions instead of a legitimate RNG determined result. Graphics were nice though. :)
Perhaps you would like the "Long War" mod for the new XCOM (and spencerflem is correct about the dash if that matters). Still one map, but it adds: - Base defence. - Larger squads of people who take more time to advance. - Bit more realistic Panic progression (and satellites / interceptor outpost bring it down AND make them less panicky. shit hits the fan if aliens will destroy either or both). - Soldiers need more time to recuperate, even without injuries they need a few days off the combat roster (which means that you should have at least thirty people to avoid late-game fight with infirmary patients :D) More detailed info (here is an archive.org version as UFOpaedia seems to fuck-up recently) Bonus :D.