Any of them, if you take the Reserves of Strength feat from Dragonlance Campaign Setting.
Reserves of Strength has two effects:
You can add +1, +2, or +3 to your caster level for a single spell, but get stunned for a number of rounds equal to the bonus you choose to add. This is a bad trade most of the time, unless you are immune to stun. (If you are immune to stun, you take that many d6s in damage, instead. This is a great trade.)
You can exceed the normal level-fixed limits of a spell with this feat
Nothing says you have to use the first part of the feat, that is, make the CL-for-stun trade, in order to activate the second part. The closest it comes to saying that is “with this feat,” but that is not nearly sufficient to mandate making the trade—after all, simply having the feat means you are casting any spell “with this feat.” Reserves of Strength is not a metamagic feat, so it doesn’t get applied to particular spells.
Furthermore, it does not say the bonuses from this feat, specifically, can exceed these limits—it says you can, “with this feat,” i.e. by virtue of having this feat. That means that it exceeding those limits is in no way limited to the bonus you choose (or not) to add to your caster level—you still get to exceed those bonuses. The feat lists a 9th-level wizard casting fireball with caster level 12th and dealing 12d6 damage, but nothing in the feat says that a 12th-level wizard, casting a CL 12th fireball, would not also deal 12d6 damage—or that a 20th-level wizard would not deal 20d6 damage. It says you exceed the limits, no ifs, ands, or buts, so that’s what you do.
And Reserves of Strength works perfectly well with spells cast from a staff:
Staffs use the spell trigger activation method, so casting a spell from a staff is usually a standard action that doesn’t provoke attacks of opportunity.
You are casting a spell “from a staff,” therefore the fact that “you can exceed the normal level-fixed limits of a spell with this feat,” applies to this spell as well as any other. Clearly, you must be the one responsible for the spell, since (barring an intelligent staff), the staff is not spending a standard action or risking an attack of opportunity.
Without Reserves of Strength
As for the more direct question of spells that have no cap to begin with, they are rare and mostly high-level. Even then, I suspect those that do exist are probably mistakes (almost-certainly the case with any lower-level spells). Certainly, the two than HeyICanChan lists, wings of flurry and venomfire, are deeply problematic spells.
Anyway, I am not aware of any resource that lists all of them, nor is this an attribute of spells that is often listed separately for searching. That would make it very difficult to compile such a list, and for the most part people don’t care—if their caster level is so high, they probably have Reserves of Strength anyway (and it’s probably a theoretical-optimization exercise to begin with). I’ll add a list if I find one, but I suspect that I will not.