I just grabbed and activated PowerCommand - really nice. I have a licence for TakeCommand/4NT 8 and I really like it as well. However, I can no longer justify the price - upgrades are $45 and come about once a year, so keeping up to date is expensive. I also have a licence for
PromptPal, courtesy of Bits du Jour. Given the huge spread in price between PromptPal and PowerCMD on one hand and TakeCommand on the other, I'd suggest that you try the GAOTD. If you don't like it, try PromptPal, which I have been very happy with... (but I'm hardly a power command line user).
EDIT: added some words here and there to improve clarity/readability. Corrected some typos.