Contentious I know, but in terms of all-round performance and looks, I'd have to say that the Parker 51 takes some beating.
The Aerometric Parker 51s (made after the early Vacumatic types) are just about bulletproof, have a great ink capacity, seldom leak or blot, the filler lasts forever being made from silicon and these pens perform exceptionally as writers. For a pen designed in 1940s, they also look modern, even today.
So, what more could you ask from a Fountain Pen and there are some still to be had for a very reasonable price?
I have to admit that when I first started collecting pens, I steered clear of P51s (too modern looking for me) and went for the early Duofolds, Conway Stewart, Onoto, Swan etc but over the years, I've found all of these ot be less than perfect as daily writers.
I use a P51 as a daily writer and even with a broad nib it behaves perfectly, I use it much more often than my much more expensive Mont Blanc 149!