A "Best Exchange Poll" already effectively exists and it constantly updated: just look at volume. People trade at their preferred exchange and "vote" with their dollars and satoshis.
That is really a good (maybe optimal) metric!
PS metatrader4 is sure on top of the list...
I would say the best combination is metatrader4 + polo-like web gui
Hi, this is my first post though I've been following bitshares for a while now. It would be ideal to have a great decentralized exchange for decentralized currencies(and more, of course).
Here is an informative link to bitcoin trading volume I recently saw. You can change the currency to reflect the market you want to see. It looks like Bitfinex is most popular in USD, OKcoin for CNY, and Kraken for EUR and there's more though I'm not sure why Polo isn't included.. maybe this is more for bitcoin rather than alts, though I think for ease of use Polo and Finex are similar. Here's USD trading volume:
http://data.bitcoinity.org/markets/volume/30d/USD?c=e&t=aThe average US crypto twitter trader, at least, seems to like Finex for very seamless and easy margin trading as bull/bear(long/short) are just two sides of the same coin, so to speak, and naturally go together. Also, OKcoin seems popular for more serious traders because it has Futures. Bitcoinwisdom is excellent for crypto charts/tools, and Tradingview for trading charts in general, not just crypto. Coinigy also seems to be great for cross-exchange trading as Chris4210X describes, though it's newer. Access to tools(metatrader4, protrader) for pro-traders seems like a great idea as well.
I also like puppies' and tbone's ideas as well as the app and trollbox suggestion to help grow the community. I found a Finex app for iPhone the other day but didn't download it because I'd prefer if it were made by the exchange creators..