What are the most famous WAN technologies used nowadays ?

MPLS

Fiber Distributed Data Interface (FDDI)Token Ring/IEEE802.5Frame RelayIntegrated Services Digital Network (ISDN) Point to Point Protocol (PPP)Switched Multimegabit Data Service (SMDS)Dial-Up TechnologiesSynchronous Data Link Control (SDLC)and Derivatives X.25 Virtual Private Networks (VPNs)Voice/Data Integration TechnologiesWirelessDigital Subscriber LineCable TechnologiesAsynchronous Transfer Mode (ATM) SwitchingMPLSData-Link Switching (DLSw)

DSL and WiMax i think

MPLS is a very widely used solution, but if you need protection for your data across the internet, IPSec vpn's would be the solution. There are different types and the best feasible could be selected as per the network design and sites involved.

MPLS is the best solution for wan connection. its best for VPN connection.

MPLS is widely available nowadays its  a better choice, Wimax could be used alternatively where MPLS is not present

MPLS is the best !! 

MPLS is the most efficient and used wan technology

wimax technology

now a day we can go with mpls 

MPLS either VPNv4 or VPLS are most famous technologies used nowadays. They are also more reliable.