I recommend the Boss GT-10B, it has a parallel effects chain, is arrangeable of all 15 effect block units in any order, and you can have all of then on at the same time.
The FX1 and FX2 blocks have identical effects so you can have 2 of everything like synths.
At the same time you can have either 4 EQ's, 3 delays, 3 Wahs, 3 compressors (one of them is a multi band), and so on..
And the Assigns make use of all the GT-10 adjustable parameters (750 of them) so you can controll up to 9 items from the press of one pedal.
Had mine since it was first released, and i am still blown away by the sound and versatility, currently i am trying out some Sansamp, SVT and Tube emulations.