I travel to Turkey once a year for a proper kebab.
I went to Fethiye back in 1996, and experienced the best doner: crispy thin meat, served simply on a slightly charred roti-type bread with onion and fresh coriander. Far beyond good.
Safadi Express opposite Holborn tube is pretty good, Lebanese grub. Had a freshly cooked chicken liver wrap the other night which was superb (if a little dribbly towards the end).