For me the Nikon D5100 is the clear winner. Read this review to know why:
http://www.amazon.com/review/R3RXULR8A4H60T/ref=cm_cr_pr_perm?ie=UTF8&ASIN=B004V4IWKG&nodeID=&linkCode=&tag=faurms-20
This camera is currently ranked as number 3 in the top 100 DSLR cameras on amazon and the D3200 is at number 13. I can compare the 2 in detail for your benefit.
A couple of advantages of the Nikon D5100 over Nikon D3200:
1.Has a flip-out screen Yes vs No
2.Has in-camera HDR Yes vs No
3.Longer battery life 660 shots vs 540 shots
4.Better boost ISO 25,600 ISO vs 12,800 ISO
5.Larger sensor APS-C 23.6x15.6mm vs APS-C 23.2x15.4mm
6.Slightly larger viewfinder 0,51x vs 0,50x
7.Slightly cheaper
Best price for Nikon D5100 from my research:
http://www.amazon.com/Nikon-16-2MP-Digital-18-55mm-3-5-5-6/dp/B004V4IWKG/ref=sr_1_1?s=electronics&ie=UTF8&qid=1337288989&sr=1-1&tag=faurms-20
Best price for Nikon D3200 from my research:
http://www.amazon.com/Nikon-Digital-18-55mm-3-5-5-6-NIKKOR/dp/B007VGGFZU/ref=sr_1_1?s=electronics&ie=UTF8&qid=1337289589&sr=1-1&tag=faurms-20