No, Deus Ex was a superb game. Deus Ex 2: Invisible War was a not so great game.
I believe there are a couple of updated versions being made of the first one. That will be very nice. I tried to get the original going but I was having some game-killing opengl issues...
As far as my favorite RPG - Tales of the Unknown Volume I: The Bards Tale.
I have to judge based not on graphics or effects.. not even solely based on story.. but on how it felt to play the game.
This was the first serious game I ever tackled. I got the disks for it from a friend of mine for the C64 - no manual or even spellbook. Somehow I got ahold of a copy of the spells by typing them all out and printing them on my Okidata 10(?) printer. (Every time you wanted to cast a spell you needed to enter the 4 character code for it - sort of a copy protection I suppose)
I sat down with a pad of graph paper and mapped out every square of that game. Skara Brae, all the dungeons.. There was just such a feeling of accomplishment when I finally beat it. Some serious nostalgia points bump this one up but in many ways a great game should be able to invoke such emotion years later.
Might and Magic II is a close second. I would get together with a friend of mine and play this one together on his Apple IIe. Another classic RPG that just got it right. I think this one even had a map feature... or at least the Eagle Eye spell..
I was always a little jealous of another friend who had a Macintosh and a copy of Wizardry: Proving Grounds of the Mad Overlord. More basic, basic graphics but it was all about building up your party and figuring out all of the little puzzles. Plus the items - I still remember him wielding the Epee' of Dismay 
Other RPG's around that time were fun - Mars Saga, The Magic Candle, Ultima IV (first one I got my hands on), Bards Tale 2: The Destiny Knight, Wasteland...
Then technology bumped us up to such gems as the gold box Pools of Radiance, Curse of the Azure Bonds, etc... very, very fun games at the time. The first two are probably among my favorite D&D titles - along with Eye of the Beholder I remember later when my girlfriend signed up for AOL and I jumped into Neverwinter Nights for the first time. Gold Box alive on the net. Too bad I couldn't afford to play 
Ultima Underworld: The Stygian Abyss was another superb game. I can still remember finally reaching the demon and his pool of lava only to discover that I had missed one of the seven(?) artifacts I needed to finish the game... not sure that I ever did find that one but very fond memories.
TES:Arena - Revolutionary. I had a blast playing this during the sporadic times that I could. I was at school at the time and had no computer of my own.. was also relatively busy blowing large, large amounts of time at the various computer labs on campus playing MUD's - Infinity to start with, then Genocide, BatMud, Battletech - and finally (and most fondly) Highlands III.
Other titles I'll mention that deserve a lot of praise are Baldur's Gate, Morrowind, Oblivion, Wizardry 8, FFVII, KOTOR, Fallout 1/2/3, Unlimited Adventures, Alternate Reality, Shining in the Darkness, Might and Magic V...
(nearly) Finally - two titles that fall into the more recent end of the timeline that I adore - Icewind Dale and Neverwinter Nights. I have never played the sequel to either but these two games were very solid.
I have also played EQ and WoW extensively... very good games in their own right but when I think of what an RPG means to me.... they just don't make it.
Apologies for the wall of text involving much more information that the OP requested.
I just like brief trips through fond memories at times...
In short: Tales of the Unknown Volume I: The Bards Tale
