Gun Mute (http://ifdb.tads.org/viewgame?id=xwedbibfksczn7eq) may be your cup of tea, unless you don't like homosexuality, Westerns, or linear games. It's definitely one of my favorites.
Snowblind Aces (http://forums.tigsource.com/index.php?topic=837.0) is heavier on the romance and lighter on the adventure, but there's an intriguing backstory.
Nightfall (http://www.wurb.com/if/game/3144) is more plot-heavy. I don't remember so much about it, unfortunately, but I remember enjoying it.
Thousand Dollar Soul (http://www.newgrounds.com/portal/view/550497) is something I've recommended on another thread. The real focus is on the plot, not the romance, and I personally think it's fascinating.