As an owner of the entire US library and every US console, it is a worthy system to buy and play with, though sadly now a days to get the complete experience it will cost you a pretty penny. For the penny pincher consumer, I would go with this route:
A Turbo Grafx 16 with the Turbo CD Add on, with the 3.0 System Card (Or japanese Acrade card pro with convertor).
This set up can be pieced together for a little less or equal amount of a Turbo Duo, but with this you get to play TG16, Turbo CD, Turbo Super CD, plus the added bonus of the Arcade card games from Japan (great ports of several SNK Games to boot).
Be warned though; lately the TG16 has become the eBay obsession, and I've seen some common games go for ridiculous prices. There are many more common cheapie games you can pick up to start, all of which are a blast to play.
There are roughly 139 games for the *entire* TG16/Duo library, and the majority are fun, worth while games. May I suggest these titles to start with, since their all HuCard based:
Ninja Spirits (think Ninja Gaiden with access to all weapons)
Bonk (any of them, Bonk 3 being a $$$ title)
Military Madness (awesome hex based strategy)
Super Star Soldier
Neutopia I + II (Or: What Zelda looks like on a TG16)
Super Lap Twin (Racing RPG!)
Splatterhouse
World Court Tennis (Uber Pong RPG!)
Bomberman (required by law to own
)
Hope ths helps,
Jason
**EDIT**
I almost forgot: The Turbo Grafx 16 is the sole reason why I stayed with video games. Were it not for a $30 TG16 with Keith Courage and Aero Blasters, I would have probably been some lonely non-gaming dope instead of the Dangerific PSX Editing / Game collecting geek I am today.
Let me know if you ever have any questions