crawfb5: If you want Rybka, then the Chess Assistant Pro package is well worth considering. Not only would you have Rybka, but CA is less expensive than a comparable ChessBase setup.If you want to get a feel for the two programs, you can download "light" versions of each. A version of CA light can be had at:
http://www.convekta.com/download.htm
A version of CB light can be had at:
http://www.chessbase.com/DOWNLOAD/c...
These light versions allow you to "test drive" the software some with a free version that has some feature restrictions (maximum number of games and/or other restrictions). The light versions might be a bit older than the commercial ones, but you can still get the feel of things, I think.
I was just about to replace a very old version of CA that wouldn't run on XP back during BoBII when I tried using SCID:
http://scid.sourceforge.net/downloa...
I've been very happy with it, and have indefinitely postponed getting one of the commercial products.
SCID or either the full-featured CA or CB will allow you to handle <large> game collections. I'm currently working with one just under 4 million games. Of course a high-quality collection would be much smaller. You could start with a large one and filter out all games with, say, both players rated 2400+ and make a new database with just those games. You will be able to use an "opening explorer" type of browsing through your collection.
Ok, where do you get games if they aren't included? Well, as a premium member, you can download batches of games here (the "zipfile directory" link on the <Premium Membership> page. You can get new games from recent events at The Week in Chess every Monday:
http://www.chess.co.uk/twic/twic\
Convenka, the Chess Assistant/Rybka company, offers similar downloads 4-5 times a month:
http://chessok.com/
There is substantial overlap between the two, and TWIC uses a <Smith, John> while Convenka uses a <Smith John> naming convention, IIRC. So unless you like reconciling player name format, probably better to stick with one or the other.
Also consider how you feel about older games. GC is currently running a little over a half million games, I think, and not all of those would make your cut. The big 3-4 million game bases are going to have a lot of older games and I don't know how far down the food chain the player ratings will go. Tim Harding talks some about the chronological breakdown in Chessbase's 4 million game database at:
http://www.chesscafe.com/text/kibit...
There are links to some free game collections at <hms123>'s forum. Again, you'd have to filter out the higher-quality games.
Hope some of this helps. What's best depends on what you want, what you're willing to spend, and what you're willing to do on your own. If you have any other questions, fire away.