I'm not really looking for "actual applications" as different ones are considered necessary by different users. What I'm looking for are performance and usability improvements without real drawkbacks. What are the improvements/hacks/changes/anything you would put on every N900 you come across? What are the ones you'd only put on your own device?

For example, I read somewhere something about moving RootFS to the main memory (and thus being able to freely scale it) and moving swap to the separate memory RootFS used to reside on. Possible benefits? Possible drawbacks? Possible at all?
Thread.
Brainstorm.

VFAT -> EXT3?

Kernel Power? I'm not going to OC, but the other features are intriguing.

Then there's the Speed Batch, which sounds great as it claims to give more priority to the currently run task than to the background tasks, as such possibly degrading multitasking performance but on the other hand providing a faster user experience.

CSSU and Hildon desktop portrait mode seem pretty obvious choices. CatorisePlus for arranging the menu.

I'm not much of a techie, which is why I can't really discuss all these in detail. I just want to reap the benefits I was thinking it might be good to have an easy-to-follow guideline somewhere for people on what recommended actions to take right after reflashing :)