Blues pedals are about feel, not flash. You need an overdrive that responds to your picking dynamics — hit soft for clean, dig in for grit. The Ibanez Tube Screamer (TS808 or TS9) has been THE blues overdrive since Stevie Ray Vaughan made it famous.
The Boss BD-2 Blues Driver is another classic — it covers a wider gain range than the Tube Screamer and works brilliantly for Texas blues and Chicago blues tones. Used prices start at $40-$60.
For a more transparent overdrive, look at the Klon Centaur (or its many clones). The EHX Soul Food and Wampler Tumnus are both affordable Klon-style overdrives that preserve your guitar's natural character while adding warmth and sustain.
Beyond overdrive, a good reverb and tremolo complete the blues pedalboard. The Boss RV-6 or TC Electronic Hall of Fame for reverb, and the Boss TR-2 or EHX Pulsar for tremolo, are all excellent used options.
