I find JSA interesting, because it mixes about three or four generations of heroes: the Golden Age Flash, Hawkman, Green Lantern, Wildcat, etc.; some Silver Age heroes, such as Black Canary; some adult heroes taking the names of Golden Age heroes, such as a new Dr. Midnight, a new Mr. Terrific, etc.; and some teenage heroes, such as Stars (a young girl with the cosmic converter belt that the old Star Spangled Kid had, as well as Starman's latest cosmic rod) and Jakeem Thunder, a kid who "inherited" the Thunderbolt from Johnny Thunder. A lot of the focus of the storyline is the older heroes acting as mentors for the younger heroes.
The latest Teen Titans (the one not connected to the TV show) involves the old Teen Titans (Nightwing, Starfire, Cyborg, Wally West Flash) gathering up the young heroes who used to be in the team Young Justice: Robin, Superboy, Impulse (who soon changes his name to Kid Flash) and Wonder Girl. I found the first several issues to be just great, with lots of wonderful character touches (Superboy to Robin: "You just lied to Starfire!" Robin to Superboy: "I lie to *Batman*.")
Also, the story of how Impulse becomes Kid Flash (which occurs over the first 2-3 issues) is just amazing, imho.
I noticed the cartoon TT was different than the comic as I'm used to it. I read it mostly in the 80s Wolfman/Perez era. The New TT you describe sounds cool--I always wished they did more with Kid Flash.
The JSA is one of my favorites--I loved the old "All Star Comics" series with the "other" Superman and Flash and GL and Hawkman, Power Girl, Dr. Midnight, Dr. Fate, Wildcat, etc.