BWtorrents is the best for me.
Maintaining ratios is not too much of a problem as all torrents except movies are ratio free. I get great speeds of around 40-80kB/s upload on 2Mb/s BSNL Broadband in between 2-8am.
I still get good uploads on highly popular TV shows like MTV Splitsville.
Also good uploading speeds are obtained on movies which have been released some 1 month ago. After 1 month, the no of seeders decrease.