Depends...
If you want a low alt fast-in fast-out attack plane...the Tiffiy is a great choice. Excellent gun platform.
If you want a long-range strategic strike and hang around for a fight, the P-51D is a good choice. Rockets + iron and 100% fuel will get you there.
If you want a town destroyer - the Bf-110G2 with heavy guns package of course. Me-410 is also decent but you're a sitting duck if someone ups from the airfield.
If you want a hanger dropper and short range - P-38L and the P-47D40.
If you want a hangar dropper and stick around for a good fight - the F6F with iron and rockets..hands down...as Slapshot suggested.
Then again, your combat preference can also depend on your choice. B&Z + iron I would go with a Fw-190F8 like Katanaso recommended.
Know your plane and what they can do - then pick the plane for the role. For example, taking a La-7 with its weak iron package on a long trip is not going to help you take down anything.
And taking a P-38L fully armed then sticking around for a turn fight with enemy Zekes Zeros and Spits will get you killed really quick. But a Ki-84 with Iron is a monster attacker - you're not going after anything however other than a town building, fuel, or a bunker.
If I was to think of which plane does everything ok - good turner, good B&Z, can turn, good fuel range, on the faster side, lots of ground attack options...it would have to the the Dog. The 51D does a lot of things ok, nothing really great - which made it a good all-around multi-purpose military aircraft.