I've always had a weakness for variegated foliage, and in the last couple of years, I've managed to accumulate quite a collection of speckled, spotted, striped, and mottled. When I went outside to take pictures of some of my variegated plants, I was shocked at just how many were out there.
Some Calla lilies have variegated leaves, such as my 'Red Galaxy.'
Caladiums are some of the most beautiful variegated plants out there. Their dramatic large leaves come in all kinds of combinations of red, pink, white and green.
Japanese Painted Fern (Athyrium niponicum var. pictum) has a frosty look to it.
Variegated leaves have a combination of plant tissue with chlorophyll and tissue without it. All variegated foliage is genetically unstable to some degree and sometimes the all-green tissue is more vigorous. If your variegated plant starts reverting and putting out new growth in solid green, just prune it out to encourage the variegated foliage to continue.
Many cultivars of Lungwort (Pulmonaria 'Trevi Fountain') have fuzzy spotted leaves and some varieties have a solid lighter green leaf with a darker green margin (such as 'Majeste').
Many heucheras exhibit some degree of variegation, but none more than 'Snow Angel.' As is often the case with variegated plants, this one is a smaller plant in general than other heucheras.
That being said, I've got a variegated hydrangea (Hydrangea macrophylla 'Variegata')and it seems to be a pretty vigorous grower.
The variegated Flowering Maple or Parlor Maple (Abutilon pictum 'Thompsonii') has a special kind of variegation caused by a virus.
Yes, that's right. It's a sick plant, but it lives quite well with its chronic illness. The mosaic virus that causes the variegation in the abutilon's leaves doesn't affect its growth or performance, but the virus can be transmitted to other non-variegated abutilons via insects such as white fly.
Sometimes the variegation isn't intentional. The leaf miners create a swirly pattern on the Columbine leaves and I don't mind it unless it gets out of hand. If you don't like the leaf miners' art work, just snip out the damaged leaves. This gets rid of the larvae that are inside the leaf munching their way through. If you know a plant is susceptible to leaf miners, like Columbine, you can spray Neem oil on the young foliage in the spring, before the miners begin damaging the leaves.
There are seven types of variegation, and Mike Hardman discusses them here, if you're interested.