Short answer: No, there is no other interactive decompiler, at least not for native codes.

Long answer: The Hex-Rays decompiler was created with the idea of interactiveness while all the other decompilers for native code that I know (I'm not talking about Java or .NET) were created as batch tools. The closest to a half interactive decompiler is Snowman, but is not really interactive (unless selecting which function you want to decompile when using the IDA Plugin is considered interactiveness.)

There is a toy "decompiler" (if the name is appropriate, as it's more a translator to pseudo-C than anything else) in Hopper but is neither interactive.

Boomerang, REC, and all the other abandoned decompiler projects that I know, were created either as command line batch tools or had a GUI just to let you select a binary.

So, as said at the beginning: the only interactive decompiler for native codes is the Hex-Rays one.

PS: I don't know why people is not focusing in the question instead of proposing their favourite tools... A disassembler is not an interactive decompiler.