I also suggest Kelly Pool. I have a group of up to 6 people playing on my single table. I am by far the best player, 4 others are sort of equal about one level below and 1 of them is a "bloody beginner" who only pockets really easy balls. That's why Kelly Pool at least gives everybody a chance to win and thus they enjoy it the most. Poker Pool did not work as well because I still won most games due to the larger selection of balls you can shoot at and thus decent position play heavily favors better players. 3-ball did not work too well either. The other option was cut-throat. The less-experienced players have a chance to team against the best player and this makes it a little harder for the best player(s).
If you want to have fun with your buddies for a longer period make sure you pick a game that is based a lot on luck else they might not enjoy playing with you for long.
And try several games, maybe your group is different. Watch closely if they still enjoy your current suggestion.
I tried many games, including Baseball, Rotation 61, 9-ball, 1-Pocket, Straight Pool, 3-ball, 7-ball, 99 and many others. But they definitely want to play Kelly Pool most times, followed by Cut-Throat and the occasional 8-ball (because that is what they only knew before we met).