More seriously, though... I think it's a simple matter of specs and mission statement. The Galaxy Class seems to have been a showcase model for Starfleet... essentially, the best of everything they had at the time in a embodiment of what I think can be safely called the Golden Age of the Federation (The time that roughly corresponds to the period between the Khitomer accords post ST:VI and the Wolf 359 incident, as it seems the Federation has been a bit of a decline from that point onward). As far as I'm given to know, these ships are continued to be maintained as such, with the latest in everything (within reason) installed on those vessels. The Intrepid class is a different animal, namely a science and research vessel, with a de-emphasis on weapons and tactical systems, a substantial size reduction and an overabundance of sensors and computing capacity. This makes it all the more bewildering that a vessel like that not only made it back from the Delta Quadrant, but, for much of it's journey, was considered one of the most powerful vessels in that area (excepting the Borg, of course) by it's denizens.
So tactically, hands down, the Galaxy Class.