Depending on your needs, I would suggest these as your priority in terms of looking for "bassy" (or at least very bass capable) but still good headphones:
Denon D5000 (discontinued; look for used/sale) (closed; semi-open)
Denon D600 (used/warehouse deal; don't buy it new, the `new' cost is ridiculous) (closed)
Ultrasone PRO 2900 (open back)
Ultrasone Signature Pro (used/deal) (closed)
Mr Speakers Mads Dog (modded T50RP) with Stax Pads (closed)
Hifiman HE-400 (open back)
AudioTechnica A900X (closed)
Beyer DT770 (premium & pro)
Beyer Custom One Pro
Audeze LCD series (used, deal, etc, over budget, but should be included since you're almost at flagship level cost)
There are bassy headphones out there that are all mid-bass bloom, like the PRO900, and most of them have awful treble spikes. Instead of trying for one of those, I would suggest a headphone that is simply warm, kinda bassy, and very bass capable instead. And then tweak to your taste of bass with different methods of equalization and/or amplifier equipment (like digizoid zo as a pre-amp, Fiio products with bass switches, etc). An example of what I mean with equalization, is dropping all frequencies by 10db except the bass frequencies you like most (for example, sub bass frequencies, in my case) as a way to bring out those frequencies more without distorting your headphone. You can make any headphone capable of dropping sub-bass tones become earthquake worth doing this.
I agree with both open Ultrasone suggestions, and would also add the Kenwood K1000 and (if the batteries aren't a problem) Bose QC15. All have some bass boost, but fit better into what Mal said - which is generally a better route than going for massive v-shaped cans (because you either end up with overwhelming bass which will get tiring after a while, or treble spikes (or both)).
With no EQ D600 has more bass than T70 for sure, David in his flagship review said that the whole Tesla line from Beyer lacks some impact. I've found the same to be true with my T1. The DT770 and DT990 line have a lot of bass at disposal.
The D600 IMO is most likely better than the D2000, maybe not as much bass, but better at everything else. I don't have the D2000 but used to have the D5000 and the 600 is quite on par with the 5000.