Here are games you should check out,
* Gabriel Knight 1-3
* Broken Sword 1-3 (4th coming out later this year)
* The Longest Journey
* other LA adventures (since you know MI, you're probably familiar with these already)
* Beneath a Steel Sky
Of course, other people will give you other recommendations. These are just my favourites.You can find people's thoughts on these games in threads like this
If you own a Nintendo DS, games like Phoenix Wright and Another Code/Trace Memory might be good choices. I quite liked them.
If you don't want another game, you could try getting into Grim Fandango fanfiction. We could always use another writer.