For West Sumatra suggest Bukittinggi and Lake Maninjau and surrounds-Padang Panjung, Payakumbuh and south of Padang an absolute paradise Painan. Check out my photos on the links on Lonely Planet Thorn Tree Indonesia forum ( pPamela).
North Sumatra- Lake Toba, Brestagi and Bukit Lawang and Tangkahan, which is a paradise and a 2 hr motor bike ride from Bukit Lawang- spent 5 days there in late Sept 2006 at Jungle Lodge.
If you can squeeze it in, Ketembe a 7 hr bus ride from Medan and a magical place to go- stay at either Pak Mus or Sadar Wisata with Iyuni and family.
