applecore mc1.7.10-1.1.0 (dependency for spice of life, hunger overhaul, hunger in peace)
Archimedes' Ships Plus v 1.7.10-1.8 Adds airships
BiblioCraft 1.11.2 Adds a variety of furniture and other fun things, like big maps
BiblioWoods Forestry Edition (bibliocraft extra mod)
BiblioWoods Natura Edition (bibliocraft extra mod)
Botania r1.7-225 plant magic
Buildcraft 7.1.15
Carpenter's Blocks 3.3.7 lets you create interesting block shapes
Chicken Shed 1.1.3 Chickens shed feathers periodically
CoFH Core 3.0.3 (dependency for thermal expansion, ect)
Craftguide 1.6.8.2 like NEI only lighter weight
Forestry for Minecraft 4.0.8.36
Hunger in Peace 1.0.0 (applecore mod) makes it so hunger goes down in peaceful mode
Hunger Overhaul 1.0.0.jenkins75 (applecore mod) makes it so hunger is more difficult to deal with
Iguana Tinker Tweaks 2.1.5 ads extra stuff to tinkers construct, might be easier to experiment with only tinkers construct first, this mod needs a lot of tweaking in configs
JourneyMap 5.1.0 A good map mod, also creates waypoints
Mantle 0.3.2a (dependency for tinkers construct and related mods)
MineTweaker 3 (used this to fix oredict entries from Plant Mega Pack)
Moveing World (dependency for Archimedes' Ships)
Natura 1.7.10-92.8a1150f Adds some trees and bushes and crops
Pams mods add many crops, foods, cooking items, and lots of pretty flowers and other plants, if you are feeling really masochistic one of them adds venus flytraps to swamps, they will damage you on contact. Her flowers work with forestry bees, also adds recipes for cactus armor/weapons, and some glass stuff.
Pam's Bonecraft 1.7.2b
Pam's Clay Spawn 1.7.10a
Pam's Get all the Seeds! 1.7.10a
Pam's HarvestCraft 1.7.10i
Pam's Random Plants 1.7.2a
Pam's Simple Recipes 1.7.2a
Pam's Temperate Plants 1.7.2b
Pam's Weeeflowers 1.7.2b
Plant Mega Pack 4.29 Adds lots of plants, can be a little overwhelming, mod owner refuses to standardize his oredict with other modders so most of his stuff isn't correctly in the oredictionary, but otherwise a very nice mod
Railcraft 9.7.00
Sophisticated Wolves 3.2.0 Makes wolves/dogs a little bit smarter/hardier
Thaumcraft 1.7.10-4.2.3.5
Spice of Life 1.2.4 (applecore mod) I have turned this off recently, makes it so there is diminishing returns on hunger/saturation if you eat the same food a lot
Thermal Expansion 4.0.3B1(CoFH mod) tech mod
Thermal Foundation 1.2.0 (CoFH mod)
Tinkers' Construct 1.8.7 (mantle dependency) adds interesting ways to craft weapons/tools, smeltery, oreberries
Tinker's Mechworks 0.2.14.100 (tinkers construct expansion) adds extension bridge and a few other little things to tinkers construct
Village Info (SSP version) 1.7.10-2.1 Lets you see village information when in or near a village
Waila 1.5.10_1.7.10 What am I looking at
Wildcaves3-0.4.7(1.7.10) Adds mushrooms, stalactites, and stalagmites to caves
Witchery adds some witchy stuff, if you want to interact with villages I recommend you turn goblins off as they kill villagers, but also count as villagers so killing goblins in a village will lower you village reputation.