We could almost write a 200 page book for you but basically, if you have
used a PC all the time for doing all that, a player will not please you
against a PC based on the formats supported and playlist support as they
all would need software from PC to handle it.
Your options are all players in the 2nd generation forums like KISS, Snazio,
Trans-Gear, Buffalo, TViX, D-Link etc... All have their pro's and cons (check
our reviews at http://www.mpcclub.com/modules.php?name=Reviews
They will get you started on narrowing down your options a bit.
Personally, the best available right now in Europe is the Snazio Net DVD
Cinema HD, despite a little cheap hardware, it has the best performance in
all our tests. If we widen our Horizon, then Zensonic Z500 would be the best.
If you looking for cheaper, look at the KISS DP-600 (299 Euro) or the Trans-Gear DVX-700 (259) which has expansion fo an internal Hard Drive including DVD support from HDD. 5beta support)
The best player for you depends on you.
No one can really say which player matches you as there are many players and many different people and needs...