I'm partial to the El Grande or Churchill (Berea), mainly because they have a nice fat section, so they are easy to grip, and they are well balanced without the cap posted on the pen while writing. They are lighter than any of the other full sized kits too. These are a little larger than the typical vintage pens, more like the oversize flat-tops from Parker or Wahl-Eversharp.
A lot of folks here like the Jr. series from Craft Supplies, or the Baron / Sedona pens from Berea, but I don't care for the combination of fat body and long, skinny metal section.
The full size versions of the Jr's are very nice looking pens, but for me just too heavy to use for any length of time. I made a Gentleman, and found that I really disliked the feel of the metal section, though it was nicely proportioned. I sold it to a friend at work, and he really likes it.
Of course, these are just my opinions, and I'm sure that many would not agree with them.
Adding one of Lou's Heritage SF nibs is an inexpensive, worthwhile upgrade.
Dan