God yes. They're both great games. They're also fairly linear, but that's really not a problem, and XIII-2 is linear in a completely convenient and fun way. So definitely. Only con is that in the first game the datalogs contain a crazy amount of vital information and update constantly.
Mai waifu: http://img62.imageshack.us/img62/3729/maiwaifu.png
Personally i loved FFXIII and enjoyed a lot FFXIII-2, so yes, imo playing those two games is great, especially since now you should be able to find them at a good price. Another good thing about FFXIII and FFXIII-2 is that there are changes between the two games so even if you play them in succession they won't feel the exact same thing (and LR will be even more different than those two).
If you are asking if you should play the first two games for LR......well, technically ir seems you would be able to play LR even as a stand-alone game, but since the story a direct continuation of Lightning's saga, imo it would be a bad idea to play LR without first playing the other two games.
"Remember, you can make anything as idiot-proof as you want, they'll just build a better idiot...."
Pros: +fun games +flashy battles +NO MP! (magic points not multiplayer, personal pro. Makes using magic much more awesome) +FF13-2 has DLC costumes of Mass Effect N7 armor and Assassins Creed Ezio Auditore. N7 Serah + Ezio Noel kicking ass on the same screen is awesome.
Cons: -Datalogs have way too much vital info that you'd miss if you dont care for reading extra junk -Haters -13-2 has a sort of dlc ending. but you can just watch it on Youtube.
Haku: You're going down, boy. Naoto: What's with this girl?