Honestly, I'm constantly tweaking my routine. I mean, I'll try something for a few weeks i.e. lift order, form, introduce new lifts, etc. But if it's not working then I make the necessary changes. All in all I haven't really revamped my entire routine since I've started lifting. I'm still growing, I'm still making progress, so I haven't had a need to. Because my lifting is very goal-oriented (police tests), I'll throw in extra lifts/exercises to prepare for particular tests. But my core program revolves around very basic lifts that will probably never change:
bench press
shoulder press
bent over row
deadlifts (I just introduced recently, actually)
squats
seated
tricep extension
bb bicep curls
These are the major players, and everything else can be subject to change/alteration.