What are the best addons for WoW ion your opinion?

I use cartographer complete, questhelper, quartz, dotimer, atlasloot enhanced, auctuioner, and titan panel.

I have Damage Meter - but switching to Recount. A must for raids.

Cartographer 3 Experimental - allot of fun

Atlas Loot - shows you instances and drops

Lightheaded - connnects to wowhead for quest notes

tomtom - coordinates

item rack - item changing very quickly

In no particular order:

Cartographer
Questhelper
Atlas loot
Recount
Omen
Dominos
ButtonFacade
Fubar
Outfitter
ATSW (AdvancedTradeSkillWindow)
Auctioneer
Bagnon
BetterInbox
Grid
GuildOrg
HeadCount
ImprovedMerchant
OmniCC
Prat
Quartz
RicoMinimap
XLoot
XLootGroup
XLootMonitor

this is very helpful post and I'd really need those addons version info too

yo,just post the links here so we can download it.Im new to this game.i dont know how to install/use those craps.Thx

Here are some must haves:

Titan Panel (a little panel at the top of your screen with lots of customizable info)
Cartographer
Atlas Loot (find out what drops in instances and from what boss)
Advanced Auctioneer (totally helps with enchanting as it has reagent helper)
Prat (sweet chat add-on)
X-Perl Unit Frames (changes the look of your group and mob windows into sleek stylish fa-shizzle)
TomTom + Lightheaded (for questing)

Also testing these:
Recount
Omen Threat Meter

These two don't seem to work for me half the time, seeing if I need to tweak em or something.

Find all of these at wow.curse.com/downloads/addons/
[url=wow.curse.com/downloads/addons/]Download Addons![/url]

here are mine:

(well known, so i think no comments needed)
AtlasLoot
Auctioneer
Cartographer
DamageMeters
Gatherer
ItemRack
OmenThreatMeter - i dont use it much cuz really few ppl have this
Quartz
QuestHelper
TitanPanel
X-Perl

and others:
AckisRecipeList - shows what recipes u still dont have and shows where to get them (some of recipes :\ )
AutoProfitX - 1 btn sell all grey items
Bagnon - single bag and bank window. Saves lots of space
Bongos3 - Alternate action bars
EvesDrop - User friendly combat log
ElkBuffBars - shows buffs and debuffs in bars. may be splited to different collumns (i made debuffs to left and buffs to right side)
Enchantrix - I think this remembers disenchanting results, but not sure...
EnhTooltip - enchanted tooltip
GroupCalendar - calendar which can synch data with guild members, keep ur notes and so on
InFlight - Shows remaining flight time between FPs
Informant - another enchanted tooltip... welll i think so...
LoatIt - Allows enable or disable addons without reloging
MinimapButtonFrame - get all buttons from minimap to single frame
MobInfo2 + MobHealth - makes DB after killing mobs with their HP, gold amount, droped items, items value....
RatingBuster - converts stats to real stats (example: 25 agility - 1% crit chance) in tooltip
ReverseEngineering - u want make Netherweave bag. U just Alt+Click on Bolt icon and mod auto makes bolts for single bag.... well not exactly this but...
SCT - scrollng combat text. Another extended combat log
SimpleRangeIndicator - shows range (0-5, 5-8,...)
SkillLevel - shows Skill lvl converted to player lvl ( 375 - 70 and so on)
SpamMeNot - blocks incoming smap and trades ( not tested much...carefull!)
TeksLoot - shows very tiny loot frames, so u can keep fighting when some noobs starts looting in middle of fight
TrinketMenu - Quick access to trinkets

later ill post screenshot with visible addons

EDIT:

ups forgot 1

OmniCC - shows CDs directly on buttons (auto changes font size and color of left time)

here is my screenshoot, not all addons visible here, but most of them wich are used all the time

I recomend Bongos3 to everyone. It takes lot of time (much more than others addons) to config, but its worth it. As my main attack is Crusader strinke, so i made biggest possible button in case of mouse usage (almost all keyboard is keybinded and its visible in screen).

Bagnon puts all bags to one window, have keyword search (non matching results are greyed) and shows item quality in cell border.

Titan have few really usefull plugins such as CritLine, ClassTracker, Durability and viable for PvP Emote (quick access to /spit xD)
Titan:Trade Cooldown - shows cooldown for items like skyfire diamonds, primal moooncloths and so on...

Simple range indicator shows... range... no more coments required

I heard some ingame thoughts that only healers must have raid frames. Its piece of shit, its must have for everyone! I tried "Grid" but xperl internal raid frames is more informative for me.

Btw, 'bout x-perl. U can easily set size of each group of frames (player, target, targettarget, party, party pet/target, raid and raid pet).

Some of addons puts big red "AGRRO" note on screen when u have it ( i think its xperl) and big blue "LOW MANA". Also one puts screen into faded red when HP is critical low ( i see it rarely =P )

And sorry for not resized screenshot in low quality...

If have any questions feel free to ask here or ingame.