TLDR: Opinions of area of interest between these subjects (specializations):
1 Algorithms
2 Programming languages
3 Business analytics
4 Pervasive computing

Hi, I'm about to choose specialisation of my software development masters. I'm almost certain what I'll go with (algorithms), but I wondered what other people thought and would choose if they had the opportunity. I'm still not too experienced in all of these areas, making the choice a bit hard :-)