Plants, mulch, outdoor furniture, various gardening and lawn care supplies. At least around here plants stay out in front of stores untouched, and lawn and garden centers leave a lot of unsecured gardening and lawn merchandise outside.
A couple of years ago I had two rather rusty wrought iron planters full of bedding plants stolen from out the front of my house. I assume they were after the scrap metal value rather than the plants, but who knows?
Not so! I’ll bet there is one in every fraternity house and “man-cave” in America! The trick is to get a real good one.
My mom is worried someone is going to break into her house and steal her 16-year old blind, deaf and stinking dog. Locks it up like Fort Knox.
“Hey! Wanna see our port-a-potty door?” Proudly: “I’m the guy who held the screwdrivers for that job.” 
Must’ve been a real chick magnet.
Pet stealing is a common crime. It’s actually more like kidnapping though. People steal a pet, wait until the owner puts up a poster promising a reward, and then they “find” the missing animal.
When I lived in Los Angeles, I had the following stolen (not all from the same location or at the same time):[ul][]JBL 4311 speaker pair[]Akai open reel recorder[]Dual 1012 turntable[]Sony 4 track audio recorder[]Pioneer professional audio recorder, worthless without the cable[]a cup of costume jewelry, worthless[]a cup of pocket change worth about a dollar[]a bicycle[]another bicycle[]two bicycles at once[]a toolbox[]a dashmount AM/FM radio[]a hairbrush[]a man’s jacket[]some old drapes[]a garden hose[]a growing, 5-ft tall marijuana plant[]an auto jack[]a worthless photo in a frame[]a digital home-built keyboard, worthless without the accompanying electronics[]the handset from a car phone (useless without the phone)[]a box of 40 year old tools[]a cellphone[]a rotary Skill sawmy Sunday paper (more than once)[/ul]So I’ve come to the conclusion that thieves will steal anything, although much of what they steal ends up in a dumpster.
Cathode ray tube TVs.
Ordinary plug-in radios.
Cuckoo clocks.
Palm Pilots.
Barbells.
Paper dictionaries.
You’d think so, but dentures and hearing aids are high-theft items in hospitals. Medicare coverage is somewhat lacking, so people will steal them and use drugstore lining kits to try to make them fit (or to sell them for the same purpose). Hearing aids are thousands or sometimes tens of thousands of dollars, and while they’ll never work really well without being programmed to you, they’ll sometimes work better than nothing - or again, be sold.
For the OP: Tomatoes in August.
Worse yet, eggplants in August.
There are a couple of Adirondack chairs that have been sitting on a lawn across the street from me for at least 20 years and at least three different owners of the house they are in front of, but nobody has tried to steal them.
A big box computer. In 1987, I helped set up a student computer lab. We had maybe 20 computers and steel cages to keep them in. Nonetheless someone broke into the locked lab and succeeded in opening one up and stealing the insides. Today, a tower sits in my office that I leave unlocked whenever I am there. Yesterday the door was unlocked for 2 1/2 hours that I was in a seminar and then coffee hour, but no one wants it. Laptops are a wholly different matter of course.
Trash cans (although a lid disappeared once, but maybe it got blown away).