There are a number of clichés related to game reviewing and Let's Players. When doing a game review series, it is desired to be as original as possible, by blending or even creating a new style of game reviewing to create something fresh. But here are some common clichés in game reviewing:
Excessive cursing and screaming Edit
A lot of game reviewers (mostly inexperienced and/or bad ones) use a lot of cursing and screaming to substitute for the lack of actual humour in their videos. These reviewers examplifies better than anything that cursing isn't necessarily funny, at least not by itself.
"The worst game ever" Edit
Some reviewers have one specific game they've reviewed and state as "the worst game I've ever played". This game will ofthen be refeered to in later reviews as a perfect example of a bad game, or it will be played as a "traumatizing and emotionally scarring experience" for humourous effect. Examples include the Angry Video Game Nerd, who's most hated and referenced games are Dr. Jekyll and Mr Hyde and Castlevania 2: Simon's Quest, Armake21, who's most hated game is Dr. Chaos, Urinatingtree and the game Batman Forever, and, to a lesser extent, Ebeeto and the game Yogi Bear.
As sad a fact as it is, stealing jokes and the styles of others is very common among game reviewers. Stealing from others is not encouraged at all, unless it's done as satire, like in the countless videos making fun of Irate Gamer by stealing jokes from recent AVGN videos. One video  (my video or my idol's video) even goes as far as pausing the review, going to Gametrailers.com, watch an AVGN video and then steal a joke from said video.