The best idea groups for blobbing are still Admin, Religious, Humanist, Diplomatic, Influence and Exploration. But the decision which of these groups you want to take early, later or not at all depends on your personal preference and the country you are playing.
Now my favourites would be Admin, Religious, Diplomatic and Exploration (situational).
Admin is just a superb mix of saving admin points and boosting your economy. I don't necessarily take it first, but I'm going to pick it up sooner or later in any game.
Religious is just a fun group with great events, Deus Vult CB (it's still worth it even though you have to complete the whole group) and it's a life saver for certain countries.
Diplomatic is also a very fun group that synergizes well with Religious and shines especially for Christian monarchies.
Exploration is arguably the strongest economic group overall and it gives you new areas to expand into, but all the micro-management involved isn't always fun.
Humanist is great but if I have already taken Religious then it means I won't take Humanist at least until the late game. It really depends on the country I'm playing.
Influence is not one of my favourites. It is a very strong group and I would take it in various situations, but I find it a bit boring because it's the generic "pick first" option.