First, the system is proportional representation with a 5 % entry barrier and vote re-distribution using the somewhat obscure D'Hondt's method, which essentially means that if you vote for a small party that is not likely to cross 5 %, your votes "fall through" and benefit the biggest parties the most. This plays a huge part in people's willingness to vote for small parties and once a small party reaches near 5 % in a poll, their preferences may skyrocket as people who were previously afraid to vote them for the risk of benefiting the big parties change their minds. This also means that the polls influence the outcome a lot and there is always talk of many polls being bought out by the powerful parties, making the small ones look dangerously low on purpose.
In the following, I will quote numbers from the latest poll that came out today, not that I believe it more, but I just have it open so what the hell. Interpret with caution. The relevant parties, in descending order of preferences, are:
ANO2011 (26.5 %) - a party led and largely controlled by Andrej Babiš, a well-known billionaire businessman from the agriculture and food industry, who currently serves as the Minister of Finances, but many would say that he effectively runs the country at the moment. A guy who makes more on subsidies than he pays on taxes and yet he earns support by fighting against the evil small businesses who do nothing but avoid taxes and steal from the hardworking citizens. Ironically, while he uses his influence to earn billions from the central budget, his biggest issue is that he abused an EU fond for some petty millions and he is now being criminally investigated for that - that's what you get for being greedy I guess. He has also likely collaborated with the communist secret police - just a couple of days ago, he lost a lawsuit in Slovakia where he wanted to be declared non-collaborator. For him and his supporters, all of this is just propaganda by the corrupt "old guard" politicians who don't want him to disrupt their shady business. What mental gymnastics are needed to think this way about a man who gets probably the largest personal financial benefit out of being in politics in the history of the country, is far beyond the reach of my tiny brain. He is also suspect in abusing the Financial Directorate (our IRS) to destroy business that compete with him or whose owners criticize him; some even speak about the danger of authoritative government should he win in a landslide, but I think it's exaggerated.
ČSSD (15.7 %) - social democracy. A party that should be the "modern left" but is still somewhat struggling with the "modern" part. An old and large party, with several "wings", one trying to appeal to poor workers, the other trying to mimic modern leftist politics, but with a too much of a penchant for regulation. They had the seat of the Prime Minister, but the dominance of ANO in the coalition has hurt their reputation a lot and their preferences are in a constant decline. Their main topic in the campaign is fight against cheap labor and steep raising of minimum wage, which makes sense (we have become the China of Europe when it comes to cheap labor), but it's probably too little too late to regain their former no. 1 spot.
KSČM (12.4 %) - the old communists, not even ashamed of being the continuation of the communist party with all its crimes. One would expect that 28 years after the revolution, their base would have slowly died out, but it still somehow doesn't happen. Includes people openly supportive of North Korean regime and other insanities, don't touch even with a two meter stick.
ODS (9.9%) - the biggest party of the 90s, now largely fallen from grace and these nearly 10 % look way too optimistic. I wouldn't even be that surprised if they don't make the cut this time. Originally a center-right party with pro-market and less social policies has devolved into yet another EU-hating anti-immigration cesspool. However trying to regain some ground with populism is pretty hard when the offer is so diverse (see later). After being tainted with scandals for years (one of them included the abuse of intelligence by the mistress of the then-Prime Minister from this party), they have a reasonable leader, but there are so many freaks in the party now that it doesn't help so much. Still, if you want lower taxes and more economic freedoms, this is the most reasonable party on the market. Unless you are gay or something.
SPD (7.1 %) - the most ironic anti-immigration party ever, spearheaded by a half-Japanese guy, Tomio Okamura. According to the great fact-checking website demagog.cz, he is the most lying major politician in the country (with Babiš from ANO not being very far behind though). Even more ironically, the name of the party is "freedom and direct democracy", while it's internally the least democratic major party, with everything being decided directly by Okamura; also famous for swiftly banning any criticism on social media. The key topics are immigrants, leaving the EU and having a referendum for everything. The biggest nightmare is if SPD+KSČM+ANO gets the majority, because not only they can construct a borderline insane government, but also it would mean that at least one of those has to be in any coalition.
TOP09 (7.0 %) - conservative center-right, less economically liberal than ODS, but still fiscally responsible. Openly pro-EU. Mostly a reasonable party, despite some tendencies for Catholic conservatism and related bullshit and some mildly populist stances against some "progressive agendas". Surprisingly social, for how they declare to not be socialists, with focus on improving healthcare, education and so on. The head (Miroslav Kalousek) is a controversial person with ties to some old corruption scandals and is a big put-off for many people, but his constant conservative values are attractive to others. The party I would vote for if it weren't for the Pirates.
Pirate party (6.6 %) - the rising star of these election, never before in parliament but have proven themselves in communal politics at many places. The actual "modern left", even though they wouldn't probably like the label so much. Started moreorless as a single-issue party, but the fight against copyright isn't even a program priority anymore - sadly for me, but understandably if they want to do actual politics. Main topics are personal freedom, digital government and transparency of government - also more of direct government which I think is misguided, but what can one do. The party is a cluster of many different opinions, including hardcore anarchists, and their internal democracy is way too wild, making them a little hard to lead, but if the current leadership persist (with the dreadlocks-wearing leader Ivan Bartoš being one the most honest politicians we ever head), they can be great - social in economical issues, yet liberal in personal freedoms, sensitive to minorities, pro-EU, pro-THC, etc... They definitely have my vote this time, but I will watch closely what happens as several other new parties have turned out to be a big disappointment in the past. Also have a terrible campaign focused on how they are not corrupt and the old politicians are, which I think is completely missing the point of why Pirates are good, but it actually brought them a lot of votes, so what the hell.
KDU-ČSL (6.2 %) - Christian Democrats, conservative social/centrist party, which in the past has shown the willingness to be in basically any government that wants them. Apart from absurd "Christian" stances against LGBT rights and such, not much to talk about.
From the parties below the cut, the most notable are the Greens (Zelení), who are actually a little more socialist form of Pirates in practice (even though their basic philosophies differ profoundly) and would also constitute an acceptable choice for me, the Libertatians (SSO) who would like the implement US-style Republican policies, including all those that demonstrably fail, such as private healthcare, which would in turn likely kill me, which makes me not very likely to vote for them and the Realists ("Realisté"), a completely new project with huge but unclear funding - their leader, a known economist, calls himself "the mentor" and they seemed to be some kind of intellectuals, until they actually opened their mouths and started spouting nationalistic crap, only in long sentences.