This is a very short list. And how does one rate the "recurrance" of a character? 2 shows? 3 shows? Multiple seasons?
System Lords are hard to add to the recurring characters list since they seemed destined to die at SG1 hands, but Lord Yu has been around for awhile. Baal has made 3 (?) appearances so I guess he counts. Nirrti showed up about the same. Chronos didn't appear much more than that. Apophis was nearly a regular for awhile and survived several demises (I've lost count.) Anubis is now the recurring bad guy we love to hate.
We've met some great Tok'ra besides Jacob/Selmak but like the System Lords, most seem destined to die. Malek has been a couple of eps, as has Freya/Anise. Martouf/Lantash was more enduring, but not immortal.
In addition to Bra'tac, there's Ry'ac (we've watched this kid grow up) and the Jaffa who saved Teal'c (character name escapes me)
There's Thor -- even if he is a puppet -- and Chaka with 3 appearances by S7.
And there's Harry Maybourne, Dr. Felger (2 shows by S7), Lt. Simmons, Maj. Davis, Dr. Kennedy, Harlan (2x) and on and on.
But my vote would go -- not to a character, but to an actor -- Dion Johnston. Look him up on IMDB and you'll see an impressive list of all those parts his played over the years on SG1, mostly hidden under latex. Now, that's recurring.