This year was the best SXSW by far because I went for work through Interscope (interscope.com) and for play through Sister Rogers (sisterrogers.com). Here are some bands I learned a lot from watching:

Hindi Zahra

Polica

Seun Kuti

Georgette

Munchi

Young Magic

Zola Jesus

Alabama Shakes

Onward Soldier

Cowboy & Indian

Tacocat

Nicky Da B

Haim

Superhumanoids

Sister Rogers

Harriet

Nick Waterhouse

Zuzuka Ponderosa

Debo Band

Janka Nabay

Foxtails Brigade

Grupo Fantasma