I confess to a bit of indulgence where pedals are concerned. My mainstay is a Line 6 M9, which I use with my T5. I like its looper a lot, sometimes to lay down an chord backing with the T5 on its most "acoustic" setting, and then perhaps with a different tone played over the top. As to which effects in the M9 are most useful (there are 100+ to choose from!) is naturally a pretty subjective topic, but at the more acoustic end of the spectrum I often use a compressor, an EQ and a reverb, with a chorus, tremelo and delay in reserve. You can keep everything subtle, or get more extreme if the song/situation so demands. The fact that you can set up a number of "scenes", each with a choice of 6 effects, and with any 3 available simultaneously, is pretty handy. The tap tempo button can be applied to delay, tremelo etc, so you can tempo-lock a series of effects together, perhaps some set with a dotted rhythm variation on the tapped tempo. Very flexible. And if you want 6 different delays, or six different EQs, etc, available under your foot that's fine - you're not limited to one instance of any one type of effect.
On a mad whim recently I bought a Electro Harmonix Freeze pedal, which is proving absolute magic! Sustain a chord/pedal note for ever, while you play along. Lost of possibilities.
I also use a Hardwire reverb pedal, which I can thoroughly recommend, especially if your amp
doesn't have any reverb built in.
Apologies for the ramble - hope it helps a bit!
Cheers
Simon