I would avoid Eldritch/Arkham, or even Flashpoint, with new gamers.
If you and your group can stomach the theme, I would recommend Letters from Whitechapel. It's a co-op hunt for Jack the Ripper that's not heavy on rules, with one player acting as Jack - so one player can play against you guys, if they're not as fond of co-op.
If the theme is too nasty, look for more family-friendly variations to the same game - Scotland Yard, Mister X, and Specter Ops (but this last one adds some needless complication to the formula).
Along another genre, you can try Codenames, which is a very popular word game played in teams. Spyfall is also pretty fun with 6, and could be categorized almost like a game of crafting the perfect question.
There are also hidden role/bluffing games - The Resistance/Avalon is excellent, but 6 is like the bare minimum you should play with. Coup is fun with 6 (I like it with the expansion).
If you want more of a deep strategy game on a board and all that, I recommend Power Grid - it's the "euro-style" game that's easy to get into, has more of a tight economic focus (with colorful paper money, even), but is a great game, especially for those just getting into the hobby.