Skype is a given on pretty much every recent tablet (Android, iPad, Windows and Kindle).
A full size SD card slot is pretty rare since most have microSD card slots. The Toshiba Excite 10 and Sony Xperia Tablet S have a full size card slot. With the iPad you can buy Apple's SD card adapter.
I believe Amazon's limits free ebook lending for Prime members to Kindle branded devices. Prime streaming video works great on Kindle tablets and the iPad, but you'll need Adobe Flash on Android tablets and Adobe has removed it from the Google Play Store, so you'd have to side-load Flash after downloading it from Adobe instead (not wildly difficult, but it is another set of steps).
-------------------- Lisa Gade Editor in Chief, MobileTechReview