Being benchmarked today at Phoronix under Linux is the HGST Travelstar 7K1000 1000GB 7200RPM Serial ATA 3.0 2.5-inch internal HDD.
I picked up this 2.5-inch HDD for a new Intel NUC Bay Trail system where I wanted a larger capacity drive and thus went for an HDD over an SSD, besides the lower cost. Eventually with this drive I'll be playing around with some encryption in conjunction with a Btrfs file-system and using transparent file-system compression. For these straightforward Linux disk benchmarks today, EXT4 was used on Ubuntu 14.04 LTS.
This 1TB laptop HDD spins at 7200 RPM, is Serial ATA 3.0 (6Gb/s) compliant, boasts a 32MB cache, offers 512 byte emulation, 4K sector sizes, The 1TB HGST Travelstar retails for just under $80 USD.