I also prefer this ending, with Anthony, but it has a begining before the flashback:

______ CONNIE
Don't worry; I'm sure he got here
on time. The roads from the
airport are so windy, it takes
forever; I've driven them myself.

She picks up some of the serving plates that he has left untouched.

CONNIE
I'll bring him out to you as soon
as he comes.

She moves back to the main house.

MED. CLOSE VIEW ON MICHAEL

He turns and looks at the rough water of the lake for a moment. He slowly takes a sip of wine.

EXT. A PLACE IN THE GARDEN - DAY

There are a few chairs.

MED. VIEW ON ANTHONY CORLEONE

He is eighteen years old.

ANTHONY
Hello, Dad.

VIEW ON MICHAEL

squinting up at his son.

MICHAEL
Anthony.

He rises, and reaches up to his son, who is now taller than
he; he embraces him.

MICHAEL
You've grown so tall... so tall in
the last year. You're much taller
than me.

ANTHONY
I was taller than you when I was
fourteen.

MICHAEL
Sit down. Your Aunt Connie and I
waited for you to have some lunch,
but now it's all dried out.

ANTHONY
I'm not hungry.

MICHAEL
Well, that's alright... alright.
Good. You'll graduate in another
year, isn't that right? You know...
I never finished college. I was a
good student, but I never
finished.
Of course, there was a war then.

Connie approaches them.

CONNIE
Don't let me interrupt anything,
this will just take a second. Here.
(she takes out a
small needle, and
begins to prepare it)
Your father has to have his insulin
shot. Why don't you go to your
room and put your things away,
Anthony.

She begins to give Michael the shot.

MICHAEL
Hurry back; we'll talk. We'll talk.

Anthony goes on his way to the house with his things.
Connie gives Michael the shot.

_____
But with this ending there could be no such part 3! Tony graduates in a year, then 20 years passed, and he still cannot get the law degree!