Seeing as Marvel gave all of these away for free a couple of weeks back, it would be rude not to give them a try.
Cable - if you had told me, back in the late 1990's that James Robinson and Carlos Pacheco were going to be the creative team in this book I would have probably exploded with anticipation. 20 years later, both creators are a pale reflection of their earlier selves. However, this book was still an entertaining read, if not really new reader friendly - there's very little in the way of introduction to the titular character or primary conflict.
Jean Grey - Dennis Hopeless' new book was a really good read. He's got a great voice for Jean, as evidenced by his Season One OGN a few years ago, and that carries on here. If you liked his Spider-Woman work this is probably worth a look too. It's almost good enough to overlook the hideous finale to his All New X-Men run.
Iceman - wasn't for me. Too much melodrama. Not interested in reading anymore.
Generation X - the original Lobdell & Bachalo run on this book was perhaps my first X-Men run, and it set the bar pretty damn high. This debut falls short of that pretty spectacularly.
X-Men: Gold - over shadowed by the Ardian Syaf controversy this was actually a decent book. Albeit quite run of the mill. I don't think Guggenheim is a creator with enough clout around which to build a whole line. His work is never going to set the world on fire.
X-Men: Blue - this, on the other hand, I did really like. Cullen Bunn's work with "the O5" here has the energy of Bendis' earlier work, but he also has a good handle on X-lore too. This could be a really cool run. Oh, and those Art Adams covers are to die for
Weapon X - was pretty cool, for what it was, but I'm really bored with the whole over-done Weapon X mythology now. It's been over-exposed in the comics and films.