Tonefactor / Mojo Hand 442 Red is favourite for me too, it sounds fabulous, and very easy to control.
The Prometheus is phenomenal (there aren't many bandpass filters around, and almost no sample & hold type controls), but it's quite finicky... (hours of fun though )
I've got the EBS BassIQ, but only use it for reverse (aww, rather than wahh...) sweeps - it's a bit 'quacky' for me in 'normal' mode...
Digitech BSW is fabulous for 'special FX' - good octave down too, but it wouldn't be my choice for an envelope filter (alone).
Boss AW-3 is good if you want or need tap-tempo wah, and some of the 'vowel' filters work quite well, but it just sounds a bit 'dead' to me somehow in the 'standard' modes.