Delphi has been around awhile and thus have a lot of different versions...
Native Ansi Versions are .... 1,2,3,4,5,6,7,2005,2006,2007
Native Unicode versions are.... 2009,2010,XE <--- XE being the latest version of Delphi
Suggested Versions... Depending if your going to make hacks or build a complete program with GUI ect.. I suggest Delphi Version 7 for anything that require small exe output and hacks ect... but gui making I would suggest the latest version of Delphi because it has some awesome features in the IDE and supports Unicode string ect.. native
There is what they call a "Lite" version of Delphi 7 which I use because its only small and has some enhancements to the IDE, also some of Delphi's inbuilt functions have been replaced with inline assembly with optimization(some functions can execute 100X faster than original).
http://delphi7lite.w ordpress.com/
Remove the space
For Delphi XE(Latest Version) goto there site and download trial version, I can send you a keygenerator to make it fully registered...
https://downloads.embarcadero.com/free/delphi
Studio version has Delphi, C++ compiler, php, .net ect...