wrenaudrey :
What are the differences between what you see in the link above?-Agility, Vertex 3, Vertex 4, Petrol, Octane, Synapse?
And lastly, what is the best bang for your buck SSD?
The old lineup (Sand Force):
Solid 3: Entry level Sand Force SSD (picked up a small one for my wife's PC last August, works like a champ so far), this product has been discontinued and merged into the Agility line
Agility 3: Use to be the Mid-level SSD, but currently it is the entry level Sand Force SSD, and what I picked up for my PC
Vertex 3: High end SSD based on Sand Force
Vertex 3 Plus: Extreme performance Sand Force, no firmware caps (it runs as fast as the flash can run), tends to have the best parts in it
The new lineup (Indilinx):
Petrol: Entry level Indilinx controller SSD. Avoid as this is a first gen product. It works, but as with any first gen product it has a few stability issues
Octane: Moderate to High performance Indilinx SSD. I have not heard the stability complaints that Petrol had on this, so it should be OK
Vertex 4: High end and Enthusiast grade Indilinx SSD
Synapse Cache is not intended to be used as a stand alone drive (though I suppose it could be used as one). Cache drives are meant to be paired with a HDD so that you have the 'reliability' and space of a HDD, but then the SSD is used to cache often used information so that you get a dramatic speed boost from those operations. As these drives are written to a lot more than a regular SSD they tend to have much better quality chips in them so that they last longer.
Sand Force vs Marvel/Indilinx:
Marvel is the generally 'better' product in that it is more stable, has better garbage collection, and a few other features. Sand Force is (or at least was) the cheap alternative, which sacrificed a little bit of stability for faster write speeds. These days though they are rough equivilant to each other, and even Intel is using Sand Force, while OCZ (typically the 'value' priced drive maker) is moving over to Indilinx which is based on Marvel. So do not think that one is clearly a better or worse platform than the other. Marvel has more consistent performance, faster reads and slower write speeds. Sand Force is a little more open for development from the company using it, so there is more variety in sandforce based products, and it reads and writes at close to the same speeds, but that speed is not quite as consistent.
To answer your question: Agility 3 or Octane are going to be the best !/$ on the OCZ lineup, with Octane being a better quality product, but as a younger product it may be more prone to problems and/or critical firmware updates (and every time you update firmware it is like reformating your drive, so it can be a pain). The Vertex line is clearly better, but you also pay a bit more for it, and the competition (Intel, and Samsung) have better products for a similar price.