So, to summarize:
- Athlon and I enjoy(ed) both sets of suggestions (to various degrees of course)
- Athlon feels his proposed set are more mainstream, both in availability (to which I guess I must agree), and in theme and treatment.
- I feel that what he calls "more mainstream" is familiarity with the manga's "boy style storytelling" only. I'd agree with the assessment only to the extent that they are the Japanese comics equivalent to most US's superheroes comics as they were in the 80's/90's (nowadays these get to be more difficult to categorize).
- My view is that if you start to read manga with no prior knowledge of them, "mainstream" is irrelevent: you should go for those that are the most appropriate for your age range for fear of getting quickly bored by the repetitiveness of Shonen manga - especially those where action/fighting/martial arts are the main theme.
Well, notwithstanding whatever anybody chooses to start with, I guess at the very least everybody will have understood that available choices are much more numerous than whatever it is you pick up first.