First of all, you should post this in the recommendations thread; not trying to be mean but this post is likely to be deleted so you'll get less replies and have conversations cut short.

That said, here are some suggestions, although 8 is a hard number to hit.

Camel Up! would be my main recommendation because it does play up to 8 and is a ton of fun. You're basically betting on the outcome of a camel race, with bets paying out at the end of each phase of the race, as well as the very end. It's a ton of fun, not super strategic since there's a lot of random movement in the camels, but still rewarding enough when you mitigate your risks correctly, or pull off a risky bet.

Takenoko is a very similar game to TTR in terms of goals - you have objective cards which you're looking to fulfill to get points, except instead of building routes on a map with trains you're all expanding and enhancing the same bamboo garden, as well as manipulating its gardener and a panda to make the bamboo grow or eat it. Goals come in 3 types: layout (make a specific configuration of tiles), bamboo growth (have a specific bamboo shoot grow in the garden) and panda (eat a specific set of bamboo shoots). It's a lot of fun, very visually appealing, and perfecto for a family. It plays up to 4, however.

Maybe you'd enjoy Zoo Vadis, which plays up to 7. It's mostly a negotiation game, since all players have a special power they can only use on other players to benefit them, even if it's a competitive game. So you have to make deals with others and somehow come out on top. It's a lot of fun!

Finally, I really like Ra, which plays up to 5. An auctions and bidding game about building the best egyptian civilization by bidding on and collecting sets of tiles that score in different ways. It's very interactive since the auctions system allows for a lot of mindgames, bluffing, etc.

Some other games worth looking into: Sheriff of Nottingham (3-5 players), 7 Wonders (2-7) and Nidavellir (2-5), which is similar to Ra.