I brought back a big bag of the green pointy mild peppers - the ones that go into menemen. Also a garlic bulb. Cost me all of 1 lira. Figs were also in season, but I wouldn't have got those home without a pile of squashed mush being at the bottom of my bag by the time the plane had landed, so I reluctantly gave them a miss.
I usually also get kilos and kilos of pistachios and a few other types of nuts, but the kids had had enought of the heat at the market before we could buy some this year.
The kids like Biskrem biscuits and "Pop Keks" which were a new one on me. From the supermarket I got some honeycomb, which was a very cheap (for me) at 3.75 TRY
Finally, we brought back a litre of Kavak white plonk ("Vino Collapso" ) which we didn't consume whilst we were there so just packed it. Useful to test the theory that some alcoholic beverages taste better in the country that they are produced rather than at home. We already have bottles of unopened Raki at home which at least partially proves the theory.
I've never been able to eat fresh tomatoes in the UK. The turkish ones are more than tolerable though.