Should I get Invisalign or crowns?

If cost is a major factor, then Invisalign is the best.  If a restorative option is possible, I would suggest porcelain veneers instead of crowns, as they are more conservative.  One advantage with veneers is the ability to avoid "ortho relapse", when teeth that were moved tend to move BACK.  Retainers are worn to keep teeth straight, but many people stop wearing them after a short while and the teeth migrate.  With veneers, the teeth tend to stay put, and there is the added benefit of changing the size, shape and color.

However, if you ARE thinking of porcelain (crowns or veneers) and changing color, then you MUST do the number of teeth that show in your smile (and 6 is NEVER enough).

You have a great smile!!!  You need a orthodontic evaluation to see if Invisalign will solve your space issues.  You may have a tooth size discrepancy which means that even if you do braces or Invisalign, you may need veneers as well.  You can whiten if the Invisalign or braces will solve your space issues and your end result is better without much treatment.  I would never do crowns if you have virgin teeth and just want spaces closed.  Another suggestion is to do bonding.  Whiten your teeth and 'bond' on plastic to close your spaces.  It is a much less invasive procedure and can be very successful.  If you ever want to do veneers, you still can.  Hope that helps-

Depending what your expectations are, Invisalign can easily close the gaps. Looking at the pictures it may take close to a year.  If further esthetic improvements are needed then cosmetic veneers may be used to reshape the contour of your smile.  Detail smile and bite analysis is needed for optimal results. However, invisalign usually improves the outcome of any cosmetic case.