Ricoh XR-X [I think that's the non US name either that or XR-M same camera different label]
Takes K mount Pentax lenses. All the features a person could want and more. Can be very cheap used.
Not tiny but not huge either. No mirror lockup. Uses AA batteries so easy to feed.
Spotmeter plus average mode. TTL flash if you want. Flash sync is only 1/100. motorwinder.
Usually sell for between $30 and $50 including a lens.