"real sound" ?
to answer this i would need to know what fake sound is. all of them produce real sound. as far as quality of audio that depends on the products not just if they are 2.0 or 2.1
"2.1 vs 2.0"
# speaker channels . # subwoofer channels. for instance 2.0 is two speakers. 2.1 is two speakers plus subwoofer. 3.1 is three speakers plus subwoofer. 7.2 is seven speakers plus two subwoofers. generally a subwoofer is needed if you want good low end bass response but otherwise is not going to affect quality
"monitor vs bookshelf vs pc"
-monitors is a broad term. generally it is used for neutral sounding speakers that are normally of bookshelf size which are self powered. generally neutral is preferred since they are used for mixing audio.
-bookshelf is a broad term referring to speaker size. this can vary to everything just above satellite size to just below floorstander. i'm not sure if there is an official list of measurements but generally anything over 5-6 inches tall and below 24 inches could be considered bookshelf. 24-36 could be called mid tower. over that floorstander and under bookshelf would be satellite. bookshelves can be self powered or passive.
-pc speakers is also a broad term. generally most are self powered and have 3.5mm inputs for easy connection to pc. some 2.0 low end models are powered by the pc output directly but are weak.
a few generic things can be said:
-home theater or hifi (monitors fall into this) speakers will sound better than pc speakers
-monitors tend towards neutral sound, home theater or hifi can have different sound signatures
-2.0 will lack the bass impact of 2.1 systems generally
-the larger the speakers the more bass they will have. some larger bookshelves can produce enough bass that unless you need the really low end you might be fine without a sub
-there are more options for passive speakers than powered.
-amplifiers generally are available as either very cheap lower output units or going with a receiver. there are not many budget to mid ranged priced medium output amplifiers out there.
i personally use a 5.1 set of passive speakers connected to a receiver. great system. in the other room we use a 2.0 system with mid-towers and a budget amplifier. this also works out great.