If RP is your main focus, it's either 2010 or 2015** (when it's done patching). Dunno about 2011 but 12 (best modding, massive understeer), 13 (very good handling, ok modding, very nice graphics) and 14 (bad clone of 13 some graphic issues, annoying sounds) had no real RP feeling.
** As an existing F1 driver, not a custom one. With talking to the box, pregrid, tv moderator before and after the race, some other minor stuff and finally like in PS2 times, being able to switch the replay focus through the whole driver grid - it adds more immersion than 12, 13 and 14 BUT there is no career mode, which is a huge downside regarding RP.