You're post is a little confusing because you site Jagged Allaince which isn't a Turn Based RPG but a turn based Strategy. If you like that game try X-Com, Silent Storm (hard to find), Age of Wonders (fantasy), Heroes of Might and Magic (fantasy).
If you are looking for real RPGs like Fallout... that is much tougher. Arcanum is the only one that comes to mind.
If you are looking for "RPGs" like Final Fantasy, track down Dragon Warrior (NES), Chrono Trigger (SNES), Dragon Warrior Monsters (GBA), Breath of Fire (PS2 or 3 I think).
All of those are "walk around on over head map, run into a monster, give orders" games.
If you want a little more control over what happens to your group try Fire Emblem, Advance Wars, or Final Fantasy Tactics (all GBA).
If you played Fallout tactics in real time also check out Ground Control.