Minecraft Mods

[Rez09]

I see you have Thaumcraft as a want and Forbidden Magic as a leftover; if you are considering running Thaumcraft it is worth including Forbidden Magic as well, as it creates interactions with other popular magic mods, usually Blood Magic and/or Botania, and expands base Thaumcraft so the Nether and Taint are actually useful to players progressing through the mod. You'd also want to include Baubles as well with Thaumcraft or Artifacts, as both mods make use of the extra armor slots it provides.

For exploration and unique items, I'd recommend bumping up The Twilight Forest on the list, as it is all about questing through different areas and fighting through unique dungeons and bosses for potentally nifty loot. Additionally, the mod offers some decorative blocks exclusive to it, such as disappearing/reappearing blocks in the Ghast Tower and trophies you can stick on your walls from the various bosses.

You might also consider Roguelike Dungeons and dimensional doors for additional dungeon content; the former is quite popular and makes challenging dungeons found in many mod packs, while the latter makes very interesting, and potentially dangerous, dungeons and allows the creation of pocket dimensions.

Extra Utilities is very popular for cheap early game power, 'natural' mob grinders, watering cans, and its quarry replacement. Though popular with a lot of people, there isn't any real need to run the mod if you have replacements for these things elsewhere and you want to keep the pack lean.
EDIT: Or if you want the builder's wand, which I completely forgot about and is a fantastic tool that makes building structures a LOT faster/easier.

I find Fossils and Archeology superior to Jurassicraft, as both do similar things by adding dinosaurs, but Fossils also adds a unique boss and Nether worldgen structures.

EnderStorage is a great mod that offers affordable long-distance item and fluid transportation, but it ultimately falls behind Ender IO and Thermal Expansion offerings for this purpose as the game progresses, and it is only really useful in combination with certain mods like Automagey.

Draconic Evolution is probably *the* current end-game mod, as it requires a lot of grinding, but the items and equipment it provides are extraordinarily powerful.

Minefactory Reloaded offers some of the best automation tools around and is generally popular because of that, especially in combination with Tinker's Construct due to the mod's Pink Slime, but most of what it does Ender IO does better; only really worth including if you want the pink slime or auto-enchanters.

EDIT:

Thaumic Tinkerer is a really odd mod, but one worth considering if you include Thaumcraft. It allows the creation of extremely high capacity wands, the general best option for equipment enchanting, and a good set of armor with creative flight. Just be careful with elemental fires from the mod, as they can do a LOT of damage.

Chisel is also probably worth moving bumping up on the list, especially if you have someone that likes decorating. It allows many mundane blocks to be turned into several spiffy variants and can add a lot of variety to pretty much any building.