Reverb is the only effect I use. I do use tube overdrive pedals too, but I don't consider them an effect. However, lately I have been using a delay and compressor on one patch for one song from my Digitech RP-155 modeler, and it is tempting me to get a compressor and a delay pedal. The RP-155 was bought for it's ability to do intelligent harmonies, and I use it for its tuner as well, but I experimented with a second sound with delay, reverb and compression, and I am suitable impressed.