There is that Aphex unit...the one with "Big Bottom".
I have the original Aphex 104 Aural Exciter Type C with Big Bottom...but there's been a couple of later/newer models since.
I have to say...I removed my Aphex from my racks several years ago, as I didn't find much use for it in recording/mixing...and it probably would be better for live work. The software plugs, IMO, do less damage and sound better.
I like the Waves Renaissance Bass for that purpose. It really does a great job of adding harmonics and fattening up the punch/presence of Bass guitar without overloading the track....and of course, you want to use it sparingly. It's very easy to get addicted and go over the top with it...and then you realize it's doing way too much.