Which is better, easier, etc? (I do the first, myself)
Depends on what you are doing and how you vision the outcome.
I do both of the first 2 myself. Depending on what type of texture I want to use. If it is a tileable/seamless texture, then I add them as I go. If it needs a more complex image or UV map, then I do it after the modelling.
BgDM
First dummy colors with the right amount of reflectance, emittance, spec etc…
dummy lighting system
almost complete modelling
almost complete lighting system
almost complete texturing
I’ll die before being finished tweaking it (up I hope)
well, i start off by thinking that i will do one of the first 2 and then i always end up doing the last one 
.
j/k
Actually, i prefer to model first and then create textures, but that’s probably because i really suck at texturing and modelling is one of my preferred things to do…
d52477001
You need to add another addition to the poll:
“barrow” textures as you go along 
hehe lol good point cough…
d52477001
Personally, I feel that to fully envision what you’re going for, it helps to have the specific model already finished. This allows for changing the model in one way or another with messing with adjusting the texture as you go. It also keeps you from (depending on the style and complexity of you’re model) becoming “Locked In” to a final result. I like being flexible in the creation process. I’ve discovered many designs that worked better than the original just by screwing around with different functions. I’d be hesitant to do that with a full texture (again, depending on complexity) in place. My 10 cents. Can I get change, please? 
Model first, assign simple materials as the model grows (makes it easier to handle later), then make the textures last. That’s usually how I do it.
This is to ensure the quality of the model. Once it looks really good in standard grey OpenGL - then it’s ready for textures.
My 8 cents (I can take the change from your 10, Merc…)
Never underestimate the effect of lighting on textures. Crappy lighting can ruin a scene as good lighting will bring out the highlights of the textures and make the scene overall much better.
Martin
if Pro:
model all stuff that you can,
then…you start to think about how massive you will make texture
I can say, a model can make or break depending on the texture,
actually, my experience say that if the texture is crappy, the scene
looks like shit, but when texture is top-notch, it looks awsome amazing !
too bad I lack good texturing skills, I need to work badly on it :-?
It depends, because most of the time I have no idea what I’m doing until it’s done. :o
I rarely texture
Stefano
well i do it this way
i model everything
then i hate it so i
remodel it all
then i hate that
so i disect it all and re-assemble it after texturing, normally in a different .blend file.
but i nearly always model everything 2 times, and texture as or jsut after modeling the second time.
Alltaken
I usually model a bit and think “Ok, this isn’t too bad… I wonder what it’s like with a texture”. Then I get totally sidetracked into making textures that look great and end up with no model for them. I really would like to be more disciplined though and wait until modelling is complete before texturing.