There are many plain objects that look interesting in some way. Here are my favorite ones.
Tools
A monk's bowl basking in the sun 1A monk's bowl basking in the sun 1 (grayscale, tinted)A monk's bowl basking in the sun 2By WaterpixelsA broom and a basket (Painting)
Sculptures
A sculpture of frog (the texture is interesting enough)The frog in context (Waterpixels)A sculpture of chickenA sculpture of chicken (Waterpixels)The chicken in context (Waterpixels)Another sculpture of chicken
A discarded hat 1A discarded hat 1 (Painting)A discarded hat 2, on a sunny dayA discarded hat 2 (Painting)A discarded hat 3, after some rainA discarded hat 4, after some more rainA discarded hat 4 (Painting)A discarded hat 4 (Oilify)