my favourite is the Sony SRS-X2
it's small, very powerful and clear audio, sounds great via BT (not tried the NFC)the battery last for ages!
the rrp for my red one is around £90, but I found it a Luton Airport Dixons for £70
caution: there are some BT speakers around that only work when you securely d/l an app from a weird website, spend 24hours trying to match your speaker with your device, then give-up! (that was another Sony!)
but the SRS-X2 is foolproof - has memory for a handful of devices - just needs a BT pairing.
(Has been tested with the likes of "Washington Bullets" from Sandinista!, "E Lucevan le Stelle" from Kaufmann/Tosca and even works with Steve Allen/LBC at the breakfast table, delivering a smooth patois of the misdeeds of 'clebs, you feel like you're in Leicester Square)