...really their Standard Series.
First off, I'm no Martin fanboy (do we even have them in the UK?). My first ever guitar was a used 1990s D1 (cheap dread) which I never really got on with (nobody should have to learn to play on a dreadnought).
And for many years, Martin's "fill every single price point" approach seemed to me to be cynical and really put me off them as a company.
Last year I acquired an OM21. It is bloody fantastic.
Last month I acquired an HD28. Again, just a great instrument.
I get that not everybody wants the Martin growly bass sound but, if you like that tone, I truly believe Martins are wonderful sounding, good value instruments. I have more expensive guitars than these (Santa Cruz, Collings & single luthier handmade) which are great - but its the Martins which I pick up.