While I'm waiting for some stocks of DJ MAX Trilogy to reach near a friend's vicinity, I resorted to playing an odd yet addictive game called, OSU!
Unlike other "music/rhythm" games (liek Audition, O2Jam, DJMAX, HS5), this one uses the mouse to play. If you have a faulty mouse, too bad for you. I have an optical mouse so I have my share of problems. Playing with a tablet is also enabled... but not recommended when doing the "spinning" (part of the game features) --- so tablets are ftw in beatmaps without spinners.
Beatmaps are MAPS or the song stages created by other OSU players. The game itself is more or less 60mb... but it only comes with a tutorial beatmap. You HAVE TO DOWNLOAD beatmaps from the official site. What's so great about this game is that it has the potential to create more and more songs everyday. Some from Anime, latest music hits, and even from other games like Audtion and DJMAX! And what's more, some beatmaps have videos in them, thereby saving the game from a bit of boredom and adding some difficulty by the video's distractions (sometiems, it's tempting to watch rather than relying on peripheral vision).
Optional for Offline Solo Play and Online Multiplayer play. You need not to connect to the internet to play. You can save your replays or merely spectate other players online.
OSU! main site
Register first before downloading beatmaps. According to the updater, it is no longer necessary to install codec softwares for the videos in some beatmaps because of the updated patch. Just follow the simple instructions when installing. Pretty darn easy enough.
There are 2 other special modes. But I liked the main mode best. Playing Osu! was my practice in mastering the pen tablet 
And a good tip for the scoring: ONE MISS is A HUGE HUGE difference! So NEVER MISS A NOTE if possible! I compared my score from a perfect play (mostly 300's and 300 elites) from a play with one mistake in the middle of the game. My perfect play was scored around 1m+ ... while the flawed play was scored 400k, Really big difference, neh? Scores are automatically saved and ranked. The highest I could reach was 38 / 1000+ players in ESTI's OBLIVION (from DJMAX Portable 2 / Fever) with Double Time and Hard Rock MOD.
The game offers MODS (built-in) to enhance game experience and add extra boosts or help while playing
Some Examples:
Double Time = increases the BPM speed to 200% (or even faster! The song and video are also affected)
Hard Rock = Smaller Circles
No Fail = You can't FAIL... ever! However, -50% score
Hidden = Invisible Circle cues
Flashlight = Yep... Flashlight mode! Limited visibility
Auto = Sit back and Relax! (doesn't record score)
Auto Pilot = same as above but you still do the clicking
Spun Out = auto-spin.... (doesn't record score either)
Sudden Death = 1 miss is failure (quite frankly, 1 miss can make you go mad when you're aiming for higher ranks)
Easy = Makes things even easier on EASY difficulty maps
1/2 Speed = zzzZZZ (snore); -70% score
No Video = If your PC can't handle the game with Video or if you want to play smoothly and get a higher rank for that song, this is a good option.
[Current fave Beatmaps:]
Cirno Chirumiru [w/ vid] --- from IOSYS. One of those Touhou(Toho) MVs
Lollipop [w/out vid] --- from BigBang feat. 2NE1 (waiting for the one with a video in it so I can laugh at Sandara Park in the opening part XD --- that caught me aback when I first saw it)
Kirameku Namida wo Hoshii ni [w/ vid]--- from Fate/Stay Night
End of the Moonlight [w/ vid] --- from DJMAX Portable 2/Fever (I heard O2Jam has this one now)
Fuwa Fuwa Time [w/ vid] --- from K-ON
Cagayake Girls (TV Size) [w/ vid] --- from K-ON
Don't say Lazy (TV Size) [w/ vid] --- from K-ON
Paradise Lost (TV Size) [w/ STRIKE WITCHES vid] --- from Ga-Rei -ZERO-
Again (TV Size) [w/ vid] --- from Fullmetal Alchemist Brotherhood
Baka ~ Baka ~ Baka [w/ vid and subs lol] --- from Vocaloid Hatsune Miku
Popipo (Vegetable Juice Song) [w/ vid and subs lol] --- from Vocaloid Hatsune Miku
Real Emotion [w/ vid from FF X-2 in-game] --- from FF X-2 (english lyrics)
Oblivion [w/ vid] --- from DJMAX Portable 2 / Fever
Memories of Beach [w/ vid] --- from DJMAX Portable 1 / Fever
We didn't start the flame war [w/ vid] --- from CollegeHumor.com
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Po~Pi~Po

Fuwa Fuwa Time ~

Seto no Hanayome OST

K-ON! ED Theme --- I <3 MIO!

Currently on the top 20... wooot!


Shakugan no Shana Second OP theme

The ever-popular Hare Hare Yukai dance XD
I got lazy so I screencapped this while setting it on Auto mode (just sit back and relax --- doesn't record score)
This post has been edited by Minasuki on Jun 21 2009, 12:03 AM