Other ones that come to mind for splashes with significant benefits are:
1 Barb for the run speed
2 Monk for evasion
1 Monk for the +2 to wisdom and saves in ocean stance for a divine
2 Rogue for UMD, Traps and Evasion
2 Fighter for 2 feats and haste boost and +1 str enhancement
2 ranger for free twf, bow strength, rapid shot
1 wizard for the metamaqic feat
1 arti for repeater use, traps and umd
The list can keep going, but I think the issue that needs adjusting are the capstones so it is more of a trade-off to splash than a significant benefit with very little lost. Hopefully this gets changed in the final enhancement pass.
Again, character design and building is a huge feature in DDO that makes it more interesting than a lot of other games imho.