twallan's Mods are worth a look. I have only NRaas Mods (Mods made by twallan) at the moment, as his are of exceptional quality, and they don't conflict with each other. He also provides a
Which Mod FAQ on his Wiki to enable you to see which Mod you would like to choose (Pick a scenario from the menu at the right).
I would suggest
ErrorTrap at first, if you are experiencing a buggy game, as well as
Overwatch. Both are beneficial to your game - ErrorTrap logs errors and usually prevents crashes, and Overwatch performs general maintenance on your game at around 3AM every game day to keep it running smooth.
If you want to enrich gameplay, consider
MasterController or
Traveler. RunAmokSims provided an explanation on the Traveler Mod, but MasterController is an excellent Mod that I use.
And finally,
Saver. It is an AutoSave mechanism so you can always guarantee you have a Save game to go to if your game does crash.
Hope this helps.