I have had good luck regarding the concert subject: I have been too quiet a few good "contestants" to this "best concert ever competition". I have three finalist: Los Bunkers in Isla de Maipo (it was free :o), Cage the Elephant and Portugal. The man in santiago and Manu Chao in Temuco <3. I think each of them are  equaly good as the other ones. How ever today I will describe Cage the Elephants and Portugal the mans concert, as its the one I most recently went to.
It was in April. Or march xd. It took place in a really small stage, so it was like a really personal show. Plus cage the elephants concerts are known for being very energetic. Specially because of their lead vocalist, that is used to jump to the audience and dance in a very  energetic way (jumps with no shirt on -crazy like-).

Interior. Sunday. Night. (jaja)
Cage  the elephant and Potugal. The mans concert.
I enter with two friends (one of them gave me the ticket(: [because his girlfriend was sick and couldnt go): ] ). Anyway we went inside and check the place out. It was really small and was not at all crowded. It was a good start. We waited a little bit, until Portugal. The man appeared and started playing really good songs (they are awesome, but not as energetic as elephant). We jumped a lot and enjoyed the show. Finally, it was the time for Cage to come out on stage: they lighted up the place in a second, with their energetic songs and moves on stage. It was awesome. We just kept dancing and jumping all around the place.
Kinda like in the middle of the concert, the vocalist took his shirt off and jumped into the audience. It was crazy. He was all over the place, he jumped back first, stomach first, head first, basically he did everything it could have been done. All in all it was an awesome show :p