Install an SSD to see a real speed bump. Depending on which Mac you have this may be a difficult upgrade. iMacs are particularly difficult for the average user and Mac Mini's are no walk in the park either, macsales.com has installation videos that will scare all but the geeks among us.
I have not tried the Hybrid drives but am considering one, a 4 terabyte (3.5 inch) can be had for a couple hundred. A 1 terabyte hybrid laptop drive will run less than $80.00, so no reason not to try one.
An SSD speeds boot up and program loads. It is not a substitute for RAM. They serve different purposes entirely. Paging memory in and out of mass storage is the main source of slowdowns. An SSD can help a lot but RAM is the real solution.