I've played Everquest 1, Vanguard:Saga of Heroes, Age of Conan. Everquest 2 has the most satisfying and dynamic combat.
Several things affect and differentiate EQ2 combat from other MMO's, IMO. They are:
ABILITY REUSE time
ABILITY RECOVERY time
ABILITY CASTING time
Typically in most MMO's you're stuck with a global cooldown on abilities. The reuse time of individual abilties being the governing factor in your effectiveness. And for the most part these things cannot be changed.
In EQ2, they can be changed dramatically. At most you can cut all 3 timers in half. So instead of a massive damage ability being 15 mins, it's now 7.5 mins. Or you go from casting an ability in 3 seconds to just 1.5 seconds, and the recovery time of 0.5 seconds goes to 0.25 seconds. This allows you to react faster to each situation, whether it be a heal, taunting or DPS (Damage per Second). It's the most satisfying as a DPS class, as you have more abilities at your disposal without having to wait, and can use them very rapidly. This lets you mix things up more, and drop certain abilities in favor of higher damage abilities on longer timers.
The other thing I enjoy about EQ2 are the graphics. I supposed I'm biased, because I've grown up playing EQ1 (1999). So I've developed an affinity to its style of art, and the appearance of racial models. (High elf female being my favorite) The graphics still use the old shader 1.0, although a lot of effort has been made to implement shader 3.0 (which still doesn't look right to me). The old shader actually makes the game look better in terms of lighting and particle effects. The lighting in this game is superb, so particle effect from spells, equipment (weapons, shields, armor) look rich, glossy and flashy. Other MMO's I've played or seen, by comparison look cheap and unimpressive due to lower particle density.
EQ2 has arguably the best looking graphics, but it comes at a price. It was developed based on CPU speed progressing in the future, so performance is largely dependant on how fast your CPU is, not your video card. As a result, to play on Extreme Quality settings with shadows enabled, at 1920x1200 resolution or greater, you're going to need at least a core 2 duo and a speed greater than 5.0 GHz. I currently run the game with an i7 980X @4.5 GHz, and get 30-60 FPS @1920x1200 (23" monitor, with vertical sync on) on Extreme Quality, but with shadows OFF. Shadows effectively cut FPS in half. You will also need a lot of RAM, as a lot of textures are stored in system RAM. So at Extreme Quality you want to have 3-4 GB RAM, which is a little excessive but only to accommodate the memory leak that becomes much more apparent on Extreme Quality, after several hours of playing.
The other nice thing about this game is that you can play it with a dial up connection, for the most part. Raiding however is going to take a *little* bit more bandwidth (around 20-30 KB/sec), due to the introduction of so many proc'ing effects with the Shadow Odyssey expansion, which adds a massive amount of spam with 24 players in a raid and attacking 10 or more mobs.
There's a lot about the game that I just don't have the room to elaborate on here. But if you're intelligent and perceptive, you'll pick up on the rest over time and with experience.
One last piece of advice for any new players. Start on the Antonia Bayle server. I moved there about a year ago, since my old raiding guild fell apart (people graduated college and spent too many hours at their new job, some were military and were deployed to Iraq, etc.). It might be labelled as a "Roleplay server" but it has evolved (like all servers do) since then, largely due to the influx of so many players. The roleplayers are now a very small minority. More importantly this server has the highest population of PvE servers, so it's the ideal community for new players.
And speaking of community, EQ2 has a lot of mature, intelligent people. Unfortunately the Antonia Bayle server does have its share of idiots too, which is present in any highly populated community. WoW is a prime example. All of the raiding guilds I have been in, are mostly professionals or college students. I'm in the minority, being neither. I suspect this is true as unlike WoW, the system requirements to truly appreciate the graphics, are quite high and thus more expensive. While this limits how many people the game can reach, it does attract a different crowd, one that is usually wealthier and presumably more educated. It's a bad stereotype but there it is.
EQ2 might have a smaller community compared to WoW, but the people make it more of an elite community. It comes down to whether you want to be around a massive amount of people, most of which are idiots, or being around *enough* people to enjoy the game, most of which are competent players and mature adults.
Oh and one last thing, if you're a new player, expect to solo for at least L60. This is because the game and server communities have evolved to the point where most people have the knowledge and expertise to very quickly reach max level, and therefore most groups are formed at max level cap (L90 as of the date of this review). One thing I found surprising about the Antonia Bayle server, unlike my old server, is occasionally very high level players will mentor lower level players and help them through dungeons or with quests. There's more of a philanthropic atmosphere here that should make new players more welcome, but like I mentioned earlier, there are some "bad apples" like you can expect in high populations- and like most negative voices/influences, they tend to have the loudest voice.