I would be hesitant to request a certain room number because you're just setting yourself up for disappointment if you don't get it.
However, we have always requested non-smoking, pool view and have never been disappointed. We've always been pleased with our rooms. Our best though had to be 5519 (I'm 99% sure that was the number). It was a corner room overlooking the quiet pool, top floor. Being on the corner it had a different layout than the usual 2-BRs and the master bedroom had a vaulted ceiling and a private balcony. Being on the corner it also had a lot of windows. We absolutely loved that room, but like I said, we were very happy with other rooms we've had at VWL as well.
I would just request what is most important to you (i.e. non-smoking, view) and be determined not to get your hopes up. Then if you do get something not quite what you were expecting you aren't really disappointed but even better if you do get just what you wanted, you'll be pleasantly suprised.
No matter the room, you're still at WDW, and even better, VWL!!!(Okay, I'm getting jealous now). Have a fun time!