My teeth are straight but my smile is lopsided or crooked, how do I fix this? (photos)

Your teeth look almost straight except that your lowers are slightly crowded. I have treated many such cases with Invisalign. Invisalign is the most natural way to move your teeth and I wouldn't suggest veneers as the shape and size of your teeth looks absolutely fine and they look well aligned. 
All you need is Invisalign for about 4-6 months to correct your smile. Hope this helps. 
Warm Regards