Distortion pedal?

Looking for good affordable distortion pedal. I'm thinking of boss md-2, Ibáñez tube screamer mini or Ibáñez ts9. Anyone can tell me which one of these is better for chugging, thrash, speed etc. metal or recommend me a good one around that price? Also the tubescreamer and the md2 are clearly cheaper. Is the ts9 worth the 20-50 or so € more? I have a Harley Benton Tube15 amp. Also maybe you have more affordable choices so I can gradually build a good pedalboard?