If LTE is not a big factor in your decision, you should go for Nexus 4. It's a great phone. However, if you think it's too big then S3 mini will be your best bet. The HTC one X is always quite an amazing android phone.
Im considering the new S3 mini as I would love to try an Android handset but dont want one of the massive tablets like the S3.
However Im struggling to jump because the Nexus 4 has much better specs...
The best sensible size handset I can see is the iphone 5...but I dont really want IOS - would like to try Android.