Mainly I use two kinds of electrolytics, Nichicon PW which is a low impedance cap. For power supplies and other general duties. Also Nichicon KL series which is a low noise cap for use in the signal path of amps and the like. Most pioneer caps will have a code on them I.E. CE04 or such, these are replaced with PW series. As a general rule of thumb, The small sky blue caps and small orange are low noise, black and medium blue are low impedance. Of course Panasonic are just as good but harder to find. Go to Mouser.com and put in your values and you will usually find a PW or KL in that size. For large capacitors it pays to shop around. I recently did an amplifier and Mouser wanted $200 for one capacitor. Newark got me both caps for the same price. I just had to wait for the pair to come from England.