Welcome to Heads-up, VideoGamer.com's weekly feature which gives you an at-a-glance run-down on the games you'll be able to buy or rent this weekend. Every Tuesday we'll pick out the best of the bunch, link to our reviews and previews and keep you in the video game loop so you have enough time to pre-order for Friday's post. Time to splash the cash.

Awarded top marks by our very own deputy editor, Mass Effect is a must buy for all fans of the RPG genre or sci-fi. Heck, it's worth buying no matter what your tastes. Mass Effect is the long-awaited title from BioWare, creator of KotOR and Jade Empire, and delivers the greatest sci-fi role-playing experience available today. A top notch story is rounded off with sublime filmic visuals and a soaring 80s synthesised soundtrack. This is a game you don't want to miss.

Guitar Hero took the video game world by storm, and now in its third iteration looks set to Rock even harder. This year the game is packed full of new features, including online play which makes it possible to rock with or against players the world over. Of course the game also includes an all-new selection of rock songs and redesigned guitars which also happen to be wireless. With Rock Band not arriving in the UK until 2008, Guitar Hero III is a no-brainer purchase for fans of peripheral-based music titles.

Despite its expansion onto home consoles, the Unreal Tournament series has always been most at home on PC so it's only right that Unreal Tournament 3 makes its debut on the platform on which the series laid its roots. It's been a long-time coming, but the latest instalment in the hugely popular multiplayer shooter looks set to deliver a slick competitive experience coupled with industry-leading visuals provided by the Unreal Engine 3. Just hope your PC is up to the job.

Mario & Sonic at the Olympic Games isn't the greatest game out this week but will surely become one of those must-have Wii party titles. Featuring a plethora of Olympic events, plus all-new Dream Events, this coming together of two of gaming's greats is perhaps the first title to capture the same spirit as the console-bundled Wii Sports. Play as one of 16 characters from the Sonic and Mario video games, each with specific skills, or compete as one of your very own Mii creations.

The flight sim is a niche genre which requires a lot of specific knowledge and skill, with gameplay all about successfully mimicking the actions of a real-world pilot. Strange then that one of the year's most exciting Xbox 360 titles falls into the very same category. However, Ace Combat 6 is not your typical flight sim, boasting glorious visuals and a Hollywood storyline that even the most fearful of flyers will find enjoyable. The only disappointment is that UK gamers don't get the rather great looking flight controller which was released in North America.

Also new this week:
Need for Speed ProStreet (Xbox 360, PS3, PS2, Wii, PC, DS)
Kane & Lynch: Dead Men (Xbox 360, PS3, PC)
Mario Party (DS)
Supreme Commander: Forged Alliance (PC)
Warhammer 40,000: Squad Command (PSP)
Code Lyoko (Wii, DS)
Final Fantasy XI: Wings of the Goddess (Xbox 360, PC)
Smarty Pants (Wii)
Elder Scrolls: Shivering Isles Add On (Xbox 360)
Cars: Mater-national (PC, PS2, DS)
Nicktoons: Attack of the Toybots (DS)
My French Coach (DS)
My Horse and Me (Wii, DS)
Jackass (PS2, PSP)
NBA 2K8 (PS3)