| Theodore Tibbitts |
This 2nd level spell completely invalidates so many other spells, core and non-core, that it needs to go. It provides a safe haven that's nearly undetectable for an hour per level. Leomund's Tiny Igloo is the same level in Frostburn, but far more obvious, silly, smaller, and less defensible. Leomund's Secure Shelter is two levels higher, and again, less defensible and more obvious, albeit larger and with explicit beds. Modernkainen's Mansion is the only alternative that is in any way better, since you can explicitly prevent access to unwanted ruffians - but it's freakin' five levels higher!
Rope Trick should have a duration of one minute per level. Enough that it can be used to hide from pursuers, but little enough it cannot be used to rest in the midst of a dungeon. Because that's just ridiculous.