Elmo Live presented in februari 2008 by 7x7toys
Please watch the gestures that Elmo makes. There are only a few basic gestures, but they are well connected to the speech. Gestures are often ambiguous and get their specific meaning through their interaction with speech. The same is true to some extent for words (their meaning sometimes relies on the accompanying gestures). In any case, by combining speech and gestures you get a very lively impression. This is what is lacking in my opinion in some of the RC-controlled robots, like the i-Sobot and the MechRC (here). They can do a couple of gestures, but without speech they are restricted to emblematic gestures that can be understood without any words. Add to this that context also does not play a role, and you get a very poor repertoire of gestures. To function properly, gestures need context, and gestures need words even more.
It should be noted that this entire episode is scripted. I do not know enough about Elmo Live but I would guess that all his stories and jokes are preprogrammed chunks.