I ended up with almost $14 in Vudu credit through Walmart purchases and activating Vudu on my TV, so I started looking through their site.
They are having a number of sales right now on Movies and TV shows.
A few that caught my attention:
Hunger Games (Vudu exclusive digital bundle) $11.99 (HDX)
The Amazing Spider-Man (Vudu exclusive digital bundle) $11.99 (HDX)
Men in Black 3 (Vudu exclusive digitial bundle) $11.99 (HDX)
... though not sure if the extra features are HD/HDX or not.
I also noticed HUGE discounts on BBC TV shows (all are HDX, unless otherwise noted):
Sherlock BBC (Digital bundle of BOTH S1 and S2) $12.99 (71% off) 
The Fades BBC Season 1 $7.99
Being Human BBC S1 $9.99
Being Human BBC S4 $12.99
Doctor Who Series 7, Part 1 $10.99
What I have determined is that Vudu needs to list prices discounts on the search pages ... cause getting even this far was PAINFUL!
A Vudu Discount thread could be worth it, having people post the deals they find.