Just wanna contribute my part of my 4 days in Penang.
Went there during Christmas,
Go by Tiger 3per @ SGD315 am flight
Back by Airasia 3 per@SGD258 evenning flight
Stay at Bayview Hotel Georgetown- 3nights @SGD240 (most Hotels fuly booked)
Near Penang Road..Daytime much activities n nightime bursting with makan n happenings at Pubs along Upper Penang Road. Another Hotel nearby is Cittel Hotel.
As what bros/sis here mentioned, all Taxis by agreed amount, most dun use meters. Anyway near these 2 hotels walking distance to all Heritage places n free shuttle bus along most of these area along a fixed route.
Gurney Drive not much better now like Spore Newton Circus n food so so.
For us, mostly walking to all places of interests.
Bukit Ferringhi n night market nothing much...nite market worst than Spore.
Like forumers said, the burger stall in front of SOHO is superb!! Every nite must tapau chicken & fish burger each!

Beat Spore Ramly Burger anytime .
Kek Lok Si temple is awesome...at least 3 hrs to wander around. Took cab (RM$40) up to temple. Walking down like going thro a tunnel of Pasar Malam.
Foodwise, good n cheap. Curry fishead just RM$14 n nasi kandar at Line Clear very good. Queue even at midnite!
Red Garden is another food venue not as much stalls as Gurney but food better.
Hope this short notes helps...