Effects Balanced by Saves

[Foryn Gilnith]

What are some relatively powerful effects whose benefits are mitigated by having to save against negative effects? Fiendish Grafts, for example, or Frenzied Berserker. I'm sort of drawing a blank right now, which is why I'm asking the Playground for help.

[Foryn Gilnith]

Any help, or are these simply an extraordinarily rare thing? I suppose intelligent items and symbionts with their Ego might count.

[PlzBreakMyCmpAn]

Many templates have will DC to not act in a certain way like 'eat the enemy who you killed with your spores' as a RAW example. Usually the DCs are trivial after some light optimization and people forget about the now trivial save.

[Thurbane]

Half-golem template requires saves to avoid becoming mindless, from memory.