Recommend good $2.49 games and 5$ one

Terraria.

Faerie Solitaire: $1.00

Cthulu Saves the World: $1.02

Eversion: $1.25

Darkstar One: $2.00 (In pack with Patrician 3 and Great Art Race)

Culpa Innata: $2.49

World of Goo: $2.50

Freedom Force 1&2: $3.74

Psychonauts: $4.99

Ceville: $5.00

Eversion can be very difficult, but it's decidedly unique and an excellent platformer that tends to get overlooked a little.
Ceville is my best I'd never heard of this at all before I used Steam purchase... terrific point and click adventure game, one of the best purchases I've made on Steam.

Oh, and this goes without saying but if you somehow don't own Trine already go buy it now. You're never going to find a better game for under $5

$5.09 Bastion, best game (with a story) Ever

Every game already listed except Orcs must die.

$1.24 ($3.72 for the 4 pack) Plain sight 4 pack, get some friends or it is not really fun, servers are dead mostly

$2.50-$3.74 Dungeons of Dredmor (dlc optional but worth it) a dungeon crawl (Diablo-esque, but it is turn based) with humor like Kingdom of Loathing, or basically the internet, or a mild 4chan. This is my type of game, but i have over 200 hours on it already. 'Don't breath this.'

$6.69 Space Chem worth the money, also in a HiB

$2.50-$5 Spectromancer /+ DLC if you like Magic the gathering, (buy this) it is made by the same guy who invented MTG (30+ dollar value for the DLC verson :-p)

$2.50 Serious Sam: The Random Encounter

$1.25 Flight control HD

$1.25 I-Fluid (you play as a drop of water in a physics based puzzle)

$2 Inside a star Filled Sky (Randomly generated maps and enemies, Deep strategy based power-up/upgrade system) pretty much infinite gameplay

$5 Puzzle Quest: Challenge of the warlords One of the coolest games ever. Bejeweled Meets an RPG, and they have a baby that takes away your will to go to work, eat, or sleep.

If you haven't played the games yet, Oddbox.

There's some great point and click style adventure games on sale. The Broken Sword triple pack is a steal at $2.49 if you somehow haven't played them yet. If you go a little higher then you can get The Longest Journey and Dreamfall for $4.99 each, $6.24 for the pair. I think TLJ is the stronger game, but they're both great.

If you want more action with your adventure, Hydrophobia: Prophecy is $2.24. It certainly has it's flaws, but for that price it's totally worth it.

Beyond Good and Evil is $6.69, but COMPLETELY worth the extra. It's a great action adventure game packed full of charm, right up there with Psychonauts at the top of the "amazing games that people didn't play" list. Incidentally, Psychonauts is $4.99 and everyone should buy it. It has achievements now!

These require more tactics if youve ever been intersted in that . Dungeons of Dredmor and binding of isaac both fun and endlessly replayable roguelikes Dredmore is more tactical while binding of isac is more actionish . I also recommend Defense grid its a TD and its really hard with a lot of replayability . Now that i look at your question again i think you might onlt like Binding of Isac out of all the games ive said but take a look at them too you might like them .

Binding of Isaac, Bastion

Painkiller: Black Edition, an amazing quake style FPS. The multi-player is dead but definitely worth the $4.99 for the single-player campaign.

Medieval II Total War Gold is 2.49, its a good game but idk if your into Strategy games, if you are Rome Total War Complete is also a nice game

Thank you for the suggestions!! :) Contenders are Defense grid, SPAZ, Puzzle Quest, alread have most of what you suggested :D. Thanks again =]

Nobody recommend Unreal Tournament yet? The 99 version is $2.50, and 2004 is $3.74.

X-Com Complete Pack is $5.09 at the moment, about as much tactical battling and replayability you could ask for the price!