Easy, powerfull, flexible with great support

Look no further, this is the one you want. The free version is fine if you are not too fussy about the translation quality (it uses the Google Translate Widget) but the pro version knocks it out of the park! And the support people are fantastic!
I had a difficult time with right to left languages breaking my template but their wonderful tech “Susanna” fixed it with a simple trick that saved me DAYS of coding.