Asking for a download link to copyrighted full Quake III Arena is illegal in this forum.
Of course, this board must NOT be used for sharing pirate links, and I don't remember such cases. However, asking for "download q3 the last version" may also have meant "the latest patch" or "a digital delivery store where to buy it"... and that has been answered.
For newcomers: Q3A engine and gamecode
source code has been released under "free" GPLv2 license (
https://github.com/id-Software/Quake-III-Arena), but its assets (maps, textures, characters, etc.) are still copyrighted, so Q3A
cannot be shared freely. Well, that's one of the reasons OA, a FREE Q3 clone, does exist (althought the "clone" word does not sound very good, maybe).