Logging in with my very first character (My Dwarf Guardian) and standing in the square of the Dwarf starting area looking out at how realistic looking the mountains were, and just listening to the wind... I was instantly hooked.
Finding the Shire for the first time on my Elf Hunter (around lvl 12) by traveling in through the north gate from Erid Luin and enjoying the shear awesomesauceness of it's atmosphere so much, I stayed for weeks and finished every quest I could find.