SanDisk Ultra 32GB MicroSD Memory Card for $15 (47¢/GB).
For portable devices that have a MicroSD (MicroSDHC) memory card slot.
Free shipping with a $35+ order, or free for Prime members.
The Cruzer Fit Flash Drives look good for adding storage to laptop computers, with having very little protruding out of the USB slot.
The Solid State Drives are meant to be put inside of laptop computers, desktop computers, and servers.
Seagate Hybrid 4TB Hard Drive with 8GB SSD for $180 (4.5¢/GB).
A 4TB hard drive provides lots of storage, and the 8GB of built-in SSD is used for caching the most frequently accessed data.
Theoretically, a hybrid hard drive should perform a little faster than a regular hard drive and is a very good choice for someone looking for a lot of storage space with good performance, however beware it will perform slower than a SSD, especially when doing writes.
For a comparison between hard drives, SSDs, and hybrid drives, see a PCWorld article.